### Home > MC1 > Chapter 8 > Lesson 8.2.4 > Problem8-69

8-69.

Evaluate the expressions below using $a = 3$, $b = –4$, and $c = 5$.

1.  $2a + c$

Replace each variable with its value.
$2\left(3\right) + 5$

Simplify the expression.
$2\left(3\right) + 5 =$
$6 + 5 = 11$

$11$

1.  $12-\left(a+b+c\right)$

Follow the steps as outlined in part (a). Remember to work within the parentheses first.

1.  $ab – 7$

Again, you can substitute each variable for its value then simplify the expression.
Remember that $ab$
means $\left(a\right)\left(b\right)$.

$-19$