In the polynomial below what number should replace the question mark to produce a difference of squares? x^2+?x-25 A.0 B.25 C.5 D.10

Question

asked Aug 11, 2019 36.1k views

2 Answers

Mike Koder · Answer 1 · 2019-08-14T03:50:07+0000

Hello from MrBillDoesMath!

Answer: A

Discussion:

An unusual question. Note that if "? = 0" then

x^2 + ?x - 25 = x^2 + 0 - 25 = x^2 - 25 = (x+5)(x-5)

Thank you,

MrB

Talha Bin Shakir · Answer 2 · 2019-08-16T15:43:36+0000

Answer:

? = 0

A is correct.

Explanation:

Given: Polynomial
x^2+?x-25

We need to make it difference of square.

It is quadratic form.

y=ax^2+bx+c

Difference of square:

y=x^2-d^2

For difference of square the x term can't be there.

Thus, The coefficient of x must be 0 for quadratic equation.

$ax^2+bx+c\rightarrow x^2-d^2$

coefficient of x must be 0

$x^2+?x-25\rightarrow x^2+0x-25$

$?\rightarrow 0$

Hence, The question marks replace by 0 to make equation perfect square.