Question

Solve 6z^2−3z=−220 by completing the square

Answer 1

See below

Explanation:

6z^2 - 3z = -220 to complete the square, the leading coeff must be 1

so divide through by 6

z^2 - 1/2 z = - 220 / 6

now take 1/2 of z coeff.....square it and add to both sides

z^2 - 1/2 z + 1/16 = - 220 / 6 + 1/16 Reduce L side

(z - 1/4)^2 = -220/6 + 1/ 16 = - 36 29/48 = - 36.6041

sqrt both sides

z - 1/4 = +- 6.0501i

z = 1/4 ± 6.0501 i