What value completes the square for the expression x^2-16x?
a.-64
b.64
c.32
d.-32
for x^2 + bx + ....
take 1/2 of the coefficient of the x term, in your case
1/2 of 16 is 8
now square that , in your case 8^2 = 64
so you would add 16 to make it into a perfect square
test:
x^2 - 16x + 64
= (x-8)^2
yup, it works.
To complete the square for the expression x^2 - 16x, we can follow these steps:
Step 1: Divide the coefficient of x by 2 and square the result.
In this case, the coefficient of x is -16, so we divide -16 by 2, which equals -8. Then we square -8, giving us 64.
Step 2: Add the result from Step 1 to both sides of the equation.
x^2 - 16x + 64
To determine the value that completes the square, we look at the constant term in the equation, which is 64. So the correct answer is (b) 64.