Answer:
the amount Deshaun invested in an account that paid 9% interest = $9,000
the amount Deshaun invested in an account that paid 5% interest = $11,000
Step-by-step explanation:
Let x = the amount Deshaun invested in an account that paid 9% interest
Let y = the amount Deshaun invested in an account that paid 5% interest.
Thus;
x + y = 20,000 - - - - (eq 1)
Now, After one year, he received a total of $1440 in interest. Thus;
0.09x + 0.05y = 1440
Multiply each term by 100 to give;
9x + 5y = 144000 ---- (eq 2)
Making x the subject in equation 1,we have;
x = 20,000 - y
Putting 20,000 - y for x in eq 2,we have;
9(20,000 - y) + 5y = 1440
180000 - 9y + 5y = 144000
180000 - 4y = 144000
180000 - 144000 = 4y
36000 = 4y
Divide both sides by 4 to give;
y = 36000/4
y = $9,000
x = 20,000 - 9000
x = $11,000
