How do you solve a+ 3( 4a + 8) = 128?

Jun 6, 2018

$a = 8$

Explanation:

$\text{distribute and simplify the left side of the equation}$

$a + 12 a + 24 = 128$

$13 a + 24 = 128$

$\text{subtract 24 from both sides}$

$13 a = 128 - 24 = 104$

$\text{divide both sides by 13}$

$a = \frac{104}{13} = 8$

$\textcolor{b l u e}{\text{As a check}}$

Substitute this value into the left side of the equation and if equal to the right side then it is the solution.

$8 + \left(3 \times 40\right) = 8 + 120 = 128 = \text{ right side}$

$a = 8 \text{ is the solution}$

Jun 6, 2018

$a = 8$

Explanation:

To solve this remember that something outside a parenthesis should be multiplied with each term inside the parenthesis.

Therefore
$a + 3 \left(4 a + 8\right) =$
$a + 12 a + 24 =$
$13 a + 24 = 128$

This gives
$13 a = 104$

$a = \frac{104}{13} = 8$