Solve for a
a=7b+27
Solve for b
b=\frac{a-27}{7}
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7b-a=-7-20
Multiply 4 and 5 to get 20.
7b-a=-27
Subtract 20 from -7 to get -27.
-a=-27-7b
Subtract 7b from both sides.
-a=-7b-27
The equation is in standard form.
\frac{-a}{-1}=\frac{-7b-27}{-1}
Divide both sides by -1.
a=\frac{-7b-27}{-1}
Dividing by -1 undoes the multiplication by -1.
a=7b+27
Divide -27-7b by -1.
7b-a=-7-20
Multiply 4 and 5 to get 20.
7b-a=-27
Subtract 20 from -7 to get -27.
7b=-27+a
Add a to both sides.
7b=a-27
The equation is in standard form.
\frac{7b}{7}=\frac{a-27}{7}
Divide both sides by 7.
b=\frac{a-27}{7}
Dividing by 7 undoes the multiplication by 7.
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