Answer:
At 5% , $300 was invested
At 15%, $4,700 was invested
Step-by-step explanation:
Let the amount invested at 5% be $x and the amount invested at 15% be $y
x + y = 5000 ••••••(i)
Let’s work with the interest;
5% of x + 15% of y = 720
0.05x + 0.15y = 720 •••••(ii)
From i;
x = 5000-y
Insert this into ii
0.05(5000-y) + 0.15y = 720
= 250 - 0.05y + 0.15y = 720
250 + 0.1y = 720
0.1y = 720-250
0.1y = 470
y = 470/0.1
y = $4700
x = 5000-y
x = 5000-4700 = $300