In mathematics, the binomial theorem is an important formula giving the expansion of powers of sums. Its simplest version reads (x+y)^n=\sum_{k=0}^n{n \choose k}x^ky^{n-k}\quad\quad\quad(1) whenever n is any non-negative integer, the numbers {n \choose k}=\frac{n!}{k!(n-k)!} are the binomial coefficients, and n! denotes the factorial of n. This formula, and the triangular arrangement of the binomial coefficients, are often attributed to Blaise Pascal who described them in the 17th century. It was, however, known to Chinese mathematician Yang Hui in the 13th century. For example, here are the cases n = 2, n = 3 and n = 4: (x + y)^2 = x^2 + 2xy + y^2\, (x + y)^3 = x^3 + 3x^2y + 3xy^2 + y^3\, (x + y)^4 = x^4 + 4x^3y + 6x^2y^2 + 4xy^3 + y^4.\, Formula (1) is valid for all real or complex numbers x and y, and more generally for any elements x and y of a semiring as long as xy = yx.

1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +

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152

50

10 x 10=100. Would you rather go like this: 1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1=100?

64

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5 5

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10

1 1 1 1 1 1 1 1 1 1 5 5 5

1 1 1 1 1 1 1 1 1 1 5 10

1 1 1 1 1 5 5 5 5

1 1 1 1 1 5 5 10

1 1 1 1 1 10 10

5 5 5 5 5

5 5 5 10

5 10 10

12 ways

1+1+1+1+1+1+1+1+1+1+1+1+1=13 3 divided by 10 = 30

I assume by "square numbers" you mean perfect squares.

You didn't say how many of each were allowed:

1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1²= 23

1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 2² = 23

1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 2² + 2² = 23

1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 3² = 23

1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 2² + 2² + 2² = 23

1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 1² + 2² + 3² = 23

1² + 1² + 1² + 1² + 1² + 1² + 1² + 2² + 2² + 2² + 2² = 23

1² + 1² + 1² + 1² + 1² + 1² + 1² + 4² = 23

1² + 1² + 1² + 1² + 1² + 3² + 3² = 23

1² + 1² + 1² + 2² + 2² + 2² + 2² + 2²= 23

1² + 1² + 1² + 2² + 4² = 23

-29

1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1

and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1

and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1

and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1

and 1 and 1 and 1 and 1 and 1 and 1.

Or

1.1 and 1.1 and 1.1 and 42.7

or an infinite number of other possibilities.

(-1)3 = (-1)(-1)(-1) = -1

(-1)3 = (-1)(-1)(-1) = -1

(-1)3 = (-1)(-1)(-1) = -1

(-1)3 = (-1)(-1)(-1) = -1

11111 x 11111 = 123454321

1 1 1 1 1

x 1 1 1 1 1

_______________

1 1 1 1 1

1 1 1 1 1

1 1 1 1 1

1 1 1 1 1

+ 1 1 1 1 1

_______________

1 2 3 4 5 4 3 2 1

[Legend: Each number represents the denomination (amount) of the coin.]

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1 = 25

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+5 = 25

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+5+5 = 25

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+10 = 25

1+1+1+1+1+1+1+1+1+1+5+5+5 = 25

1+1+1+1+1+5+5+10 = 25

1+1+1+1+1+5+5+5+5 = 25

1+1+1+1+1+10+10 = 25

5+5+5+5+5 = 25

5+5+5+10 = 25

5+10+10 = 25

So the answer is 11!!!

I think you're missing 1+1+1+1+1+1+1+1+1+1+5+10 = 25 ?

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1 is one example.

20

The answer is -1.

(1 + 1 x 1)/(1 - 1 x 1 -1) + 1 =

Follow the order of operations: parentheses/brackets, exponents, multiplication and division from left to right, and addition and subtraction from left to right.

Numerator:

Simplify 1 x 1 to 1.

(1 + 1)/(1 - 1 x 1 -1) + 1

Simplify 1 + 1 to 2.

2/(1 - 1 x 1 - 1) + 1

Denominator:

Simplify 1 x 1 to 1.

2/(1 - 1 - 1) + 1

Simplify 1 - 1 - 1 to -1.

2/(-1) +1

Simplify 2/(-1) to -2.

-2 +1

Simplify.

-1

11

There are infinitely many possible solutions. One of them is

1 + 1 + 1 + 1 + 1 + 1 +1 + 1 + 1 + 1 +

1 + 1 + 1 + 1 + 1 + 1 +1 + 1 + 1 + 1 +

1 + 1 + 1 + 1 + 12

1+1 is 2 and 1-1 is 0 and 1*1 is 1 and 1/1 is 1

23

One possibility:

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1 x 0

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1x0=

They are -1 and +1.

They are -1 and +1.

They are -1 and +1.

They are -1 and +1.

1 quarter, 2 dimes, 2 nickels, and 45 pennies

1+2+2+45=50

25+10+10+5+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1=100

1 quarter, 2 dimes, 2 nickels, and 45 pennies.

1+2+2+45=50

25+10+10+5+5+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1

The reciprocal of 1 is 1.

Proof:

a. 1*(1/1) = 1 because a*(1/a) = 1

b. 1*1 =1 because 1*a = a

c. 1/1 = 1 compare a. and b.

1+1-1+1-1+1-1+1-1+1-1+1-1+1-1*0+2

1 x 1 x 1 x 1 x 1 x 1 x 1 x 1 x 1 = 19

1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 12 1 11 1 1 1

There are infinitely many possible answers.

One such is 1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+16

It is negative infinity.

A series if digits

1

There are infinitely many possible answers:

One possible answer:

-1 and - 1 and - 1 and - 1 and - 1 and - 1 and - 1 and - 1

that is (-1) + (-1) + (-1) + (-1) + (-1) + (-1) + (-1) + (-1)

1+1+1+1+1+1+1+1+1-1+1+1+1+1x0=

1 x ( 1/1) = 1 ; -1 (1/-1) = 1

(1+1)×(1+1) +1+1

it is 8

1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 11 - 9,999,999 = - 9,999,978

you take 1 of the 1s and put it in the tenths place. Then you add the 1+1+1+1+1 and put the answer(5) in the ones place! that is how you get 15 out of 1 1 1 1 1 1.

1+1+1+1+254

1+1+1+2+253

1+1+1+3+252

1+1+1+4+251

and

1*1*1*1*258

Inelegant solution.

Maximum effort.

100-1-1-1-1-1-1-1=

99-1-1-1-1-1-1=

98-1-1-1-1-1=

97-1-1-1-1=

96-1-1-1=

95-1-1

94-1=

93

..... ..... ..... ..... ..... ..... ..... .....

Elegant solution.

Minimum effort.

100-1-1-1-1-1-1-1=

100-7=

93

2+2+2+2+2+2+2+1

or

1+1+1+1+1+1+1+1+1+1+1+1+1+1+1