Solve for x
x=3
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3x+7x-21=9
Use the distributive property to multiply 7 by x-3.
10x-21=9
Combine 3x and 7x to get 10x.
10x=9+21
Add 21 to both sides.
10x=30
Add 9 and 21 to get 30.
x=\frac{30}{10}
Divide both sides by 10.
x=3
Divide 30 by 10 to get 3.
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