Answer:
solve for x, see below
Explanation:
not gonna completely solve this cause that's cheating, but I'll set the equations up
1) write equation with x as # months and set gyms A and B = eachother
$195 + $35x = $85 + $45x where x is the number of months to get to the equal point, now solve for x
Subtract 85 from both sides, then subtract 35x from both sides. Then divide both sides by 10
2) Melissa earns $387 per week plus $15x (x is the number of subscribers)
so last week is $507 = $387 + $15x now solve for x. Subtract $387 from both sides, then divide both sides by 15