Question

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

Options: A) 5/2 B) 5/4 C) 25/4

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-(5)/(2))^(2) =x^(2) -2*(5)/(2)x+((5)/(2))^(2)\\ \\= x^(2) -5x+((25)/(4))`

therefore

the answer is the option C

`(25)/(4)`