Question 821594
Solve:
4z + 9 = 7(z + 3) - 5z

            I'm not sure what the question is asking me to do, or how to do it.
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What question?
It's an equation.
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Question don't ask things, anyway.  Questions are asked.
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 Can someone help me understand the equation and how to solve it?
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Solve:
4z + 9 = 7(z + 3) - 5z
4z + 9 = 7z + 21 - 5z
4z + 9 = 2z + 21
2z + 9 = 21
2z = 12
z = 6