Solving word problems with 2 variables

So I figured out most of this chapter but in the exercises they give you problems that they don't even give examples of in the book

Can someone please show me how to do these step by step?

http://i1209.photobucket.com/albums/...g?t=1333821915

Number 35, with x and y variables. I just need to know how I would format this problem

2012-04-07130457.jpg picture by King_Bradley - Photobucket

Number 43

2012-04-07130841.jpg picture by King_Bradley - Photobucket

Number 17

I just need to know how to format these problems with 2 variables representing something

Re: Solving word problems with 2 variables

#35. Mahmud invested $6000 in two accounts, some of it at 4% simple interest, the rest of it in an account earning 2% simple interest. How much did he invest in each account if he earned $190 in interest after 1 year?

Start by "naming" things. Let "x" be the amount of money invested at 4% interest. The interest on that is .04x. Let "y" be the amount invested at 2% interest. The interest on that is .02y.

The total invested is $6000: x+ y= 6000

The total interest is $190: .04x+ .02y= 190.

Solve that, then try the others.