quadratic equation

Question

Solve the quadratic equation by completing the square: z²+16z−36=−1z2+16z-36=-1 

Give the equation after completing the square, but before taking the square root. Your answer should look like: (z−a)²=b(z-a)²=b 

A) The equation is:

B) z=:

Answer 1

z^2+16z-36=-1

= z^2 +16z +64 = 35 +64

take half of 16, square it, add it to both sides

the equation before taking the square root is:

=(z+8)^2 = 99

then

z+8 = +/- 3sqr11

z= 3sqr11 - 8 or -3sqr11 - 8