Can someone please help me with these two.

1." A total of 12,000 is invested in two funds paying 9% and 11% simple interest. If the yearly interest is $1,180, how much of the 12,000 is invested at each rate?

**USE A MATRIX METHOD TO SOLVE THIS QUESTION.**"

Mr F says: The two equations you need to solve simltaneously are:

x + y = 12,000 .... (1) .... (2) I'll assume I've done the heavy lifting and that you can express equations (1) and (2) as a matrix equation, and that you can solve this matrix equation (reviewing your class notes and/or textbook might help here).
2. x^2 + y^2=57

.... (1)
x+2y=1

=> x = 1 - 2y .... (2) Mr F says: Start by substituting (2) into (1) and solving the resulting quadratic equation for y .....
[snip]