math algebra
posted by scooby .
Bayside Insurance offers two health plans. Under plan A, Giselle would have to pay the first $70 of her medical bills, plus 30% of the rest. Under plan B, Giselle would pay the first $170, but only 20% of the rest. For what amount of medical bills will plan B save Giselle money? Assume she has over $170 in bills. Giselle would save with plan B if she had more than $___ in bills.

Where the plans would be equal is found by the following formula:
.3x + 70 = .2x + 170
Solve for x. Giselle would save on plan B once the costs exceed that amount.
I hope this helps. Thanks for asking.