Solve for x
x=7
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3x-9=12
Multiply both sides by 12.
3x=12+9
Add 9 to both sides.
3x=21
Add 12 and 9 to get 21.
x=\frac{21}{3}
Divide both sides by 3.
x=7
Divide 21 by 3 to get 7.
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