Question

Dimitri is solving the equation x2 – 10x = 21. Which value must be added to both sides of the equation to make the left side a perfect-square trinomial?

Answer 1

Answer:

$\boxed{\sf \ \ 25 \ \ }$

Step-by-step explanation:

Hello,

we can see that

$x^2-10x = x^2-2*5x$

is the beginning of

$x^2-2*5x+5^2=(x-5)^2$

so we must add 5*5=25 to both sides of the equation to make the left side a perfect square trinomial

hope this helps

Answer 2

Answer:

25.

Step-by-step explanation:

To find the value that will make the left side a perfect-square trinomial, you need to find (b/2)^2. In this case, b = -10.

(-10 / 2)^2

= (-5)^2

= (-5) * (-5)

= 25

Once you add 25 to both sides, the left side becomes x^2 - 10x + 25, which is equal to (x - 5)^2.

Hope this helps!