Problema Solution
Select the set of equations that represents the following situation: Mary invested one amount at 1% simple interest, and a second amount at 6% interest, earning $17.68 in one year. If she had switched the amounts, she would have earned $14.04. What were the two amounts
Answer provided by our tutors
0.01(x) +0.06(y) = 17.68
0.01(y) + 0.06(x) = 14.04
we can solve this using the elimination method
0.01(x) +0.06(y) = 17.68
(0.01(y) + 0.06(x) = 14.04)(-6)
0.01(x) +0.06(y) = 17.68
(-0.06(y) - 0.36(x) = -84.24)
Add the two equations:
-0.35(x) = -66.56
the two amounts are:
x = 190.171
y = (-0.01(190.171) + 17.68)/0.06 = 262.971