Solve for x
x=7
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-13=3x+15-7x
Use the distributive property to multiply 3 by x+5.
-13=-4x+15
Combine 3x and -7x to get -4x.
-4x+15=-13
Swap sides so that all variable terms are on the left hand side.
-4x=-13-15
Subtract 15 from both sides.
-4x=-28
Subtract 15 from -13 to get -28.
x=\frac{-28}{-4}
Divide both sides by -4.
x=7
Divide -28 by -4 to get 7.
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