Solve for a 5a+c=-8a

$5 a + c = - 8 a$

Move all terms containing $a$ to the left side of the equation.

Add $8 a$ to both sides of the equation.

$5 a + c + 8 a = 0$

Add $5 a$ and $8 a$ .

$13 a + c = 0$

Subtract $c$ from both sides of the equation.

$13 a = - c$

Divide each term in $13 a = - c$ by $13$ and simplify.

Divide each term in $13 a = - c$ by $13$ .

$\frac{13 a}{13} = \frac{- c}{13}$

Simplify the left side.

Cancel the common factor of $13$ .

Cancel the common factor.

$\frac{13 a}{13} = \frac{- c}{13}$

Divide $a$ by $1$ .

$a = \frac{- c}{13}$

Simplify the right side.

Move the negative in front of the fraction.

$a = - \frac{c}{13}$