Solve for a (15-a)/3=-9

$\frac{15 - a}{3} = - 9$

Multiply both sides by $3$ .

$\frac{15 - a}{3} \cdot 3 = - 9 \cdot 3$

Simplify.

Simplify the left side.

Simplify $\frac{15 - a}{3} \cdot 3$ .

Cancel the common factor of $3$ .

Cancel the common factor.

$\frac{15 - a}{3} \cdot 3 = - 9 \cdot 3$

Rewrite the expression.

$15 - a = - 9 \cdot 3$

Reorder $15$ and $- a$ .

$- a + 15 = - 9 \cdot 3$

Simplify the right side.

Multiply $- 9$ by $3$ .

$- a + 15 = - 27$

Solve for $a$ .

Move all terms not containing $a$ to the right side of the equation.

Subtract $15$ from both sides of the equation.

$- a = - 27 - 15$

Subtract $15$ from $- 27$ .

$- a = - 42$

Divide each term in $- a = - 42$ by $- 1$ and simplify.

Divide each term in $- a = - 42$ by $- 1$ .

$\frac{- a}{- 1} = \frac{- 42}{- 1}$

Simplify the left side.

Dividing two negative values results in a positive value.

$\frac{a}{1} = \frac{- 42}{- 1}$

Divide $a$ by $1$ .

$a = \frac{- 42}{- 1}$

Simplify the right side.

Divide $- 42$ by $- 1$ .

$a = 42$