Question

Which of the following numbers must be added to complete the square in the equation below? x^2-13x+4 = 17

A. 169
B .13/2
C. 169/4
D . -169/4​

Answer 1

To make a perfect square we need to rewrite the equation in way that it will be easier to solve.

The format is ax² - bx =

Hence our equation will be x² -13x = 17 - 4

x² -13x = 13

we now have to apply the formula; (b/2)² = AC

(-13/2)² = 1 X c

c = 169/4

The answer is therefore C.