00:02
Rocco borrowed a total of $5 ,000 from two student loans.
00:06
So we're going to call those student loans x and y, and the total is $5 ,000.
00:13
One loan charged 3 % simple interest and the other charged 2 .5 % simple interest, both payable after graduation.
00:20
If the interest he owed after one year was $132 .50, we're going to determine the principal for each loan.
00:28
So the first loan had 3 % interest, and we're going to write that interest as a decimal.
00:33
0 .03 times x plus 0 .025 times y equals that interest of 132 .5.
00:44
We're going to use substitution here.
00:48
Over here on the x plus y equals 5 ,000, i'm going to solve this for x by subtracting y from both sides.
00:54
We get x equals 5 ,000 minus y.
00:57
I can go over here now and substitute that in and we get 0 .03 times 5 ,000.
01:03
Minus y plus 0 .025y equals 132 .5...