Find amount invested in each account

Question

Mardi received an inheritance of $50,000.she invested part of it at 12% and deposited the remainder in tax free bonds at 9%.her total annual interest from the investment was $5700.find the amount invested in each account Account 

Answer 1

x + y = 50000 => 0.12x+0.12y=6000
0.12x + 0.09y = 5700
deduct equation on both sides, it gets: 0.03y = 300, so y=10000
x = 50000-10000=40000
 
40000 invested in 12%
10000 invested in 9%

Answer 2

You have two unknowns and you can express them in 2 equations

A + B = $50,000

A*.12 + B*.09 = $5,700

 

Now express A in terms of B

 

A = 50,000 - B and substitute in the second equation

($50,000 - B)* .12 + B * .09 = $5,700

$6,000 - .12B + .09B = $5,700

$300 = .03B

$300 / .03 = B

B = 10,000

 

Now substitute into the first equation to find A, which is obviously $40,000

 

Answer 3

x + y = 50000 => 0.12x+0.12y=6000

0.12x + 0.09y = 5700

deduct equation on both sides, it gets: 0.03y = 300, so y=10000

x = 50000-10000=40000

 

40000 invested in 12%

10000 invested in 9%