Question

solve for r.
8 + 4r = 9r + r - 10
r = \boxed{}

Explanation:

Step1: Combine like terms on the right

$9r + r - 10 = 10r - 10$

Step2: Subtract 4r from both sides

$8 + 4r - 4r = 10r - 10 - 4r$
$8 = 6r - 10$

Step3: Add 10 to both sides

$8 + 10 = 6r - 10 + 10$
$18 = 6r$

Step4: Divide both sides by 6

$\frac{18}{6} = \frac{6r}{6}$
$3 = r$

Answer:

$3$