Answer:
$658
Step-by-step explanation:
42 x 99 = 4,158
4,158 - 3,500 = 658
Treat this as if the inequality sign was the same thing as an equal sign. Most of the equality rules apply to inequalities (with a few exceptions)

Subtract both sides by 4


Multiply both sides by 2


We want the unknown variable on the left side (because it looks nicer)

Answer:
3•10^3 is 3,000, so the answer is 9,000