ou notice that the following problem cannot be factored so you solve it by completing the square. What value of x would make the left - hand side of this equation a perfect square trinomial? x^2 - 8x + c = 13

a. 16
b. 4
c. 64
d.-8
f. -4

To complete the square for the equation x^2 - 8x + c = 13, you need to find the value of c that would make the left-hand side a perfect square trinomial.

The formula for completing the square for a quadratic equation of the form ax^2 + bx + c = 0 is to add and subtract (b/2)^2 to the equation. In this case, b = -8, so (b/2)^2 = (-8/2)^2 = 16.

So, to make x^2 - 8x + c a perfect square trinomial, c should be 16. Therefore, the answer is:

a. 16