Solve for x
x=\frac{x_{3}-80}{4}
Solve for x_3
x_{3}=4\left(x+20\right)
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80=x_{3}-4x
Combine -5x and x to get -4x.
x_{3}-4x=80
Swap sides so that all variable terms are on the left hand side.
-4x=80-x_{3}
Subtract x_{3} from both sides.
\frac{-4x}{-4}=\frac{80-x_{3}}{-4}
Divide both sides by -4.
x=\frac{80-x_{3}}{-4}
Dividing by -4 undoes the multiplication by -4.
x=\frac{x_{3}}{4}-20
Divide 80-x_{3} by -4.
80=x_{3}-4x
Combine -5x and x to get -4x.
x_{3}-4x=80
Swap sides so that all variable terms are on the left hand side.
x_{3}=80+4x
Add 4x to both sides.
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