00:01
So a person invested a total of $8 ,300 for one year.
00:09
And we put x in, the investment that earned only 4%.
00:17
Y is the amount earning 9%.
00:25
And z is the amount earning 14%.
00:29
So then x plus y plus z has to be 80 through 300.
00:37
And the interest earned over the year is going to be 0 .04 times x plus 0 .09 times y plus 0 .14 times z.
00:52
And that was 892.
00:56
And the amount of money invested at 14%, which is z, was $500 more than the amount invested at 4 % and 9 % combined.
01:09
So 400 plus x plus y combined.
01:15
And now we want to find x, y, and z.
01:17
Well, i have three equations, three unknowns.
01:20
My first equation is x plus y plus z is 8 ,300.
01:27
The second one is, if i multiply that through by 100, i get 4x plus 9y plus 14z is 89200.
01:43
And then the second one is that x plus y minus z is negative 500...