Question

Complete the expression so it forms a perfect-square trinomial. x² - 5x +

Answer 1

25/4 because the 25 and 4 can be square rooted to 5/2

Answer 2

we know that

$(x-a)^{2} =x^{2} -2ax+a^{2}$

we have

$x^{2}- 5x + (\ )$

in this problem

$-2ax=-5x\\2a=5\\a=(5/2)$

Substitute

$(x-\frac{5}{2})^{2} =x^{2} -2*\frac{5}{2}x+(\frac{5}{2})^{2}\\ \\= x^{2} -5x+(\frac{25}{4})$

therefore

the answer is the option C

$\frac{25}{4}$