a = 4b + 35,000
0.09b + 0.11a = 40,950
Substitute.
0.09b + 0.11(4b + 35,000) = 40,950
0.09b + 0.44b + 3850 = 40,950
0.53b + 3850 = 40,950
0.53b + 3850 - 3850 = 40,950 - 3850
0.53b = 37,100
b = 70,000
a = 4b + 35,000
a = 4(70,000) + 35,000
a = 280,000 + 35,000
a = 315,000
He invested $315,000 at 11% and $70,000 at 9%.
Lazara T.
great explanation, you made it very understandable10/05/19