Solve for a -3(-2a-4)+25=-3(5a+9)+1

$- 3 (- 2 a - 4) + 25 = - 3 (5 a + 9) + 1$

Simplify $- 3 (- 2 a - 4) + 25$ .

Simplify each term.

Apply the distributive property.

$- 3 (- 2 a) - 3 \cdot - 4 + 25 = - 3 (5 a + 9) + 1$

Multiply $- 2$ by $- 3$ .

$6 a - 3 \cdot - 4 + 25 = - 3 (5 a + 9) + 1$

Multiply $- 3$ by $- 4$ .

$6 a + 12 + 25 = - 3 (5 a + 9) + 1$

Add $12$ and $25$ .

$6 a + 37 = - 3 (5 a + 9) + 1$

Simplify $- 3 (5 a + 9) + 1$ .

Simplify each term.

Apply the distributive property.

$6 a + 37 = - 3 (5 a) - 3 \cdot 9 + 1$

Multiply $5$ by $- 3$ .

$6 a + 37 = - 15 a - 3 \cdot 9 + 1$

Multiply $- 3$ by $9$ .

$6 a + 37 = - 15 a - 27 + 1$

Add $- 27$ and $1$ .

$6 a + 37 = - 15 a - 26$

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

Add $15 a$ to both sides of the equation.

$6 a + 37 + 15 a = - 26$

Add $6 a$ and $15 a$ .

$21 a + 37 = - 26$

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

Subtract $37$ from both sides of the equation.

$21 a = - 26 - 37$

Subtract $37$ from $- 26$ .

$21 a = - 63$

Divide each term in $21 a = - 63$ by $21$ and simplify.

Divide each term in $21 a = - 63$ by $21$ .

$\frac{21 a}{21} = \frac{- 63}{21}$

Simplify the left side.

Cancel the common factor of $21$ .

Cancel the common factor.

$\frac{21 a}{21} = \frac{- 63}{21}$

Divide $a$ by $1$ .

$a = \frac{- 63}{21}$

Simplify the right side.

Divide $- 63$ by $21$ .

$a = - 3$