SOLUTION: -2(4z+5)>-6-4z

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Question 751819: -2(4z+5)>-6-4z
Found 2 solutions by rfer, lenny460:
Answer by rfer(16322) (Show Source):
You can put this solution on YOUR website!
-8z-10 > -6-4z
-8z+4z > -6+10
-4z > 4
z < -1

Answer by lenny460(1073) (Show Source):
You can put this solution on YOUR website!
-2(4z+5) > -6-4z

-2 * 4z = -8z
-2 * 5 = -10
Therefore:
-8z - 10 > -6 - 4z
Add 10 to each side of the inequality.
-8z - 10 + 10 > -6 - 4z + 10
Combine like terms:
-10 + 10 = 0
-6 + 10 = 4
We now have:
-8z > 4 - 4z
Add 4z to each side of the inequality.
-8z + 4z > 4 - 4z + 4z
Combine like terms:
-8z + 4z = -4z
-4z + 4z = 0
Therefore:
-4z > 4
Divide each side by -4
z < -1

Please note: When you divide an inequality by a negative number you flip (change) the inequality sign.

Answer:
z < -1

Lennox Obuong
Algebra Tutor
Nairobi, Kenya
Email: obuong3@aol.com