# How do you solve 5(a-1)-15=3(a+2)+4?

Mar 3, 2018

$a = 15$

#### Explanation:

First, use the distributive property on the parentheses and combine like terms
$5 \left(a - 1\right) - 15 = 3 \left(a + 2\right) + 4$
$5 a - 5 - 15 = 3 a + 6 + 4$
$5 a - 20 = 3 a + 10$

Then, subtract 3a from both sides
$2 a - 20 = 10$

Finally, solve for a
$2 a - 20 = 10$
$a = 15$

Now that we know what a is, we can substitute for a in the original equation
$5 \left(15 - 1\right) - 15 = 3 \left(15 + 2\right) + 4$
$75 - 5 - 15 = 45 + 6 + 4$
$55 = 55$ (correct)

We can now conclude that a is equal to 15