Mr. Oliver invested a total of $6400, part at 9% per year and the remainder at 8% per year. At the end of 2 years and 6 months, he had earced a total investment of $1380 in simple interest. How much ded he invest at each rate.

I have to come up with the equation.

5 answers

.09x+.08x(30)= $1380 + $6400 = ?

......i think/hope that this is right....
Bex, I have to have 2 different numbers. I have to find out how much he invested at each individual rate.
I have .09x + .08(6400 - x)=1380.
This equation is not correct. Someone please help me!!
sorry.im not very good at algebra =[
.09x+.08x(30)= $1380 + $6400 =

(Multiply .08 X 30 = 2.4)

.09x + 2.4x = 7780
3.3x = 7780

3.3x $7780
---- = -----
3.3 3.3

x = $2357.57
i need 9 factors of 4x squared