Question

What value for C will make the expression a perfect square trinomial x2-7x+c

Answer 1

Answer:

The value of c is 12.25

Step-by-step explanation:

we know that

A perfect square trinomial is of the form

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

In this problem we have

$x^{2}-7x+c$

so

equate the equations

$x^{2}-7x+c=x^{2}-2ax+a^{2}$

we have

the following equations

$-7x=-2ax$ -----> equation A

and

$c=a^{2}$ -----> equation B

Solve the equation A

$-7x=-2ax$

$7=2a$

$a=3.5$

Solve the equation B

$c=a^{2}$

$c=3.5^{2}=12.25$

therefore

$(x-3.5)^{2}=x^{2}-7x+12.25$

The value of c is 12.25

Answer 2

Answer:

49/4

Step-by-step explanation:

To make x2-7x+c a perfect square trinomial we do it by completing the square method. First, make half of the coefficient of x then add and subtract by squaring it. c=49/4 this is the required value of c.