SOLUTION: How do i solve: zē + 8z + 7 ≤ 0

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Question 410187: How do i solve:
zē + 8z + 7 ≤ 0
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
z%5E2+%2B+8z+%2B+7+%3C=+0
Solve by completing the square
z%5E2+%2B+8z+%2B+%288%2F2%29%5E2+%3C=+%288%2F2%29%5E2+-+7
z%5E2+%2B+8z+%2B+16+%3C=+16+-+7
%28z+%2B+4%29%5E2+%3C=+11
z+%2B+4+%3C=+sqrt%2811%29
z+%3C=+sqrt%2811%29+-+4
and
z+%3C=+-sqrt%2811%29+-+4