Answer:
amount invested at 4% = $22,000
amount invested at 5.5% = $17,000
amount invested at 6% = $11,000
Explanation:
step 1:
A = amount at 4%
B = amount at 5.5%
0.5A = amount at 6%
step 2:
A + B +0.5A = 50,000
1.5A + B = 50,000
0.04A + 0.055B + (0.06 x 0.5A) = 2,475
0.04A + 0.055B + 0.03A = 2,475
0.07A + 0.055B = 2,475
step 3:
1.5A + B = 50,000 ←←← multiply by -0.055
0.07A + 0.055B = 2,475
-0.0825A - 0.005B = -2,750
0.07A + 0.055B = 2,475
step 4:
-0.0125A = -275
step 5:
A = -275 / (-0.0125) = $22,000 = amount invested at 4%
0.5 x 22,000 = $11,000 = amount invested at 6%
33,000 + B = 50,000 ⇒ B = $17,000 = amount invested at 5.5%