algebra
posted by susan flowers .
Select the set of equations that represents the following situation: Mary invested one amount at 7% simple interest, and a second amount at 5% interest, earning $29.80 in one year. If she had switched the amounts, she would have earned $35.00. What were the two amounts?

x and y
.07 x + .05 y = 29.80
.05 x + .07 y = 35.00
7 x + 5 y = 2980
5 x + 7 y = 3500
35 x + 25 y = 14900
35 x + 49 y = 24500

 24 y =  9600
y = 400
go back and get x