$\displaystyle \frac{1}{2}x-6=3$

Add $\displaystyle 6$ to both sides of the equation.

$\displaystyle \frac{1}{2}x-6+6=3+6$

$\displaystyle \frac{1}{2}x=9$

Multiply both sides of the equation by $\displaystyle 2$.

$\displaystyle \frac{1}{2}x(2)=9(2)$

$\displaystyle x=18$

$\displaystyle \frac{1}{5}a-7=-2$

Add $\displaystyle 7$ to both sides of the equation.

$\displaystyle \frac{1}{5}a-7+7=-2+7$

$\displaystyle \frac{1}{5}a=5$

Multiply both sides of the equation by $\displaystyle 5$.

$\displaystyle \frac{1}{5}a(5)=5(5)$

$\displaystyle a=25$

$\displaystyle 12b+56=200$

Subtract $\displaystyle 56$ from both sides of the equation.

$\displaystyle 12b+56-56=200-56$

$\displaystyle 12b=144$

Divide both sides of the equation by $\displaystyle 12$.

$\displaystyle \frac{12b}{12}=\frac{144}{12}$

$\displaystyle b=12$

$\displaystyle -\frac{1}{3}c+9=6$

Subtract $\displaystyle 9$ from both sides of the equation.

$\displaystyle -\frac{1}{3}c+9-9=6-9$

$\displaystyle -\frac{1}{3}c=-3$

Multiply both sides of the equation by $\displaystyle -3$.

$\displaystyle -\frac{1}{3}c(-3)=-3(-3)$

$\displaystyle c=9$

$\displaystyle \frac{4}{5}d+16=20$

Subtract $\displaystyle 16$ from both sides of the equation.

$\displaystyle \frac{4}{5}d+16-16=20-16$

$\displaystyle \frac{4}{5}d=4$

Multiply both sides of the equation by $\displaystyle \frac{5}{4}$.

$\displaystyle \left ( \frac{5}{4}\right )\frac{4}{5}d=\frac{4}{1}\left ( \frac{5}{4} \right )$

$\displaystyle d=\frac{20}{4}$

$\displaystyle d=5$

$\displaystyle -7e+16=219$

Subtract $\displaystyle 16$ from both sides of the equation.

$\displaystyle -7e+16-16=219-16$

$\displaystyle -7e=203$

Divide both sides of the equation by $\displaystyle -7$.

$\displaystyle \frac{-7c}{-7}=\frac{203}{-7}$

$\displaystyle e=-29$

$\displaystyle 6f+9=117$

Subtract $\displaystyle 9$ from both sides of the equation.

$\displaystyle 6f+9-9=117-9$

$\displaystyle 6f=108$

Divide both sides of the equation by $\displaystyle 6$.

$\displaystyle \frac{6f}{6}=\frac{108}{6}$

$\displaystyle f=18$

$\displaystyle 17-\frac{1}{4}g=2$

Subtract $\displaystyle 17$ from both sides of the equation.

$\displaystyle 17-17-\frac{1}{4}g=2-17$

$\displaystyle -\frac{1}{4}g=-15$

Multiply both sides by $\displaystyle -4$.

$\displaystyle (-4)-\frac{1}{4}g=-15(-4)$

$\displaystyle g=60$

$\displaystyle 0.25c+4=-1$

Subtract $\displaystyle 4$ from both sides of the equation.

$\displaystyle 0.25c+4-4=(-1)-4$

$\displaystyle 0.25c=-5$

Divide both sides of the equation by $\displaystyle 0.25$.

$\displaystyle \frac{0.25c}{0.25}=\frac{-5}{0.25}$

Substitute $\displaystyle 4$ for $\displaystyle 0.25$ because:

$\displaystyle 0.25=\frac{1}{4}$

$\displaystyle c=\frac{5}{4}$

$\displaystyle c=-20$

$\displaystyle 3a+5=17$

Subtract $\displaystyle 5$ from both sides of the equation.

$\displaystyle 3a+5-5=17-5$

$\displaystyle 3a=12$

Divide both sides of the equation by $\displaystyle 3$.

$\displaystyle \frac{3a}{3}=\frac{12}{3}$

$\displaystyle a=4$