Question

solve for r.
-0.9 + 0.88r = 0.09 + 0.77r
r = \boxed{}

Explanation:

Step1: Isolate r terms on left

Subtract $0.77r$ from both sides:
$-0.9 + 0.88r - 0.77r = 0.09 + 0.77r - 0.77r$
$-0.9 + 0.11r = 0.09$

Step2: Isolate constant terms on right

Add $0.9$ to both sides:
$-0.9 + 0.11r + 0.9 = 0.09 + 0.9$
$0.11r = 0.99$

Step3: Solve for r

Divide both sides by $0.11$:
$r = \frac{0.99}{0.11}$

Answer:

$9$