What's the formula and the answer?
How would you solve this:
Ralph invests $15,600 into two different acconunts; a savings account and checking account. Thr savings account earns 8% interest. The checking account earns 9% interest. After 1 year he earned $1334.28 interest. How much did Raph invest into each account?
+23254 Let s represent the amount in the savings account ---> the amount earned in the savings account is 0.08s.
Let c be the amount in the checking account ---> the amount earned in the checking account is 0.09c
Total, they earned $1334.28 ---> 0.08s + 0.09c = 1334.28
Before the two accounts earned any interest, they totaled $15,600.00 ---> s + c = 15,600.
We need to solve these two equations simultaneously:
0.08s + 0.09c = 1334.28
s + c = 15,600
One way to do this is by substitution:
first, solve the second equation for c ---> c = 15,600 - s
then, substitute this value back into the first equation:
0.08s + 0.09c = 1334.28
---> 0.08s + 0.09(15600 - s) = 1334.27
---> 0.08s + 1404 - 0.09s = 1334.27
---> 1404 - 0.01s = 1334.27
---> -0.01s = -69.73
---> s = $6973.00
Since c = 15600 - s, c = 15600 - 6973 = $8627.00
+23254 Let s represent the amount in the savings account ---> the amount earned in the savings account is 0.08s.
Let c be the amount in the checking account ---> the amount earned in the checking account is 0.09c
Total, they earned $1334.28 ---> 0.08s + 0.09c = 1334.28
Before the two accounts earned any interest, they totaled $15,600.00 ---> s + c = 15,600.
We need to solve these two equations simultaneously:
0.08s + 0.09c = 1334.28
s + c = 15,600
One way to do this is by substitution:
first, solve the second equation for c ---> c = 15,600 - s
then, substitute this value back into the first equation:
0.08s + 0.09c = 1334.28
---> 0.08s + 0.09(15600 - s) = 1334.27
---> 0.08s + 1404 - 0.09s = 1334.27
---> 1404 - 0.01s = 1334.27
---> -0.01s = -69.73
---> s = $6973.00
Since c = 15600 - s, c = 15600 - 6973 = $8627.00
