math
posted by Kristen .
Bayside Insurance offers two health plans. Under plan A, Giselle would pay the first $150 of her medical bills, plus 40% of the rest. Under plan B, Giselle would pay the first $250, but only 35% of the rest. For what amount of medical bills will plan B save Giselle money? Assume she has over $250 in bills.

Let X be the amount of medical bills. Plan A cost:
C(A) = 150 + 0.40(X150)
Plan B cost:
C(B) = 250 + 0.35(X250)
Set C(A) = C(B) and solve for the breakeven value of X.
C(A)= 0.40(X150)
= C(B) = 250 + 0.35(X250)