00:01
All right, so lucky you.
00:04
You inherited $100 ,000 and you smartly decide to invest it into three accounts.
00:11
One pays 4%, one pays 3%, one pays 2%.
00:15
I don't know why you wouldn't put it all in a 4 % account, but after one year, you have $3 ,650.
00:23
And we're also told that the amount in the 4 % account is 5 times the amount that's in the...
00:31
3 % account so at least they put most of their money in the 4 % account right so 360 $3 ,650 interest after one year so you inherited a hundred thousand dollars so if we add up the investments here that should be 100 ,000 so we start off by saying that x plus y plus z is equal to 100 ,000 and then we know the interest after one year is 30 3 ,650 so that would be 0 .04x plus 0 .03y plus 0 .02z and that equals 3 ,650.
01:29
And the final one is the money that's in the 4 % account equals 5 times the amount of money in the 3 % account.
01:40
All right okay so first things first let's go ahead and substitute our 5 y for our x's in these equations so my first equation becomes 5 y 5 y plus y so that'd be 6y plus z equals 100 ,000 and then 5 times 0 .04 is 0 .04 is 0 .2.
02:26
So i've got 0 .2y here and 0 .03.
02:33
So 0 .23 plus 0 .02x is equal to 3 ,650.
02:53
All right.
02:55
And i want to try to cancel these things out, cancel a variable...