Can someone help me set this problem up?

1. The area of a rectangular field is 1200m^2. Two parallel sides are fenced with aluminum at $20/m. The remaining two sides are fenced with steel at $10/m. The total cost of the fencing is $2200.

a) What is the length of each side fenced with aluminum?
b) What is the length of each side fenced with steel?

You have two equations with two unknown:

Let x = the side with aluminum @$20/m
Let y = the side with steel @$10/m

Here are your two equations:

(x)(y) = 1200 sq.meters

(2 sides)($20/side)(x) + (2 sides)($10/side) = $2,200

From the first equation, x = 1200/y

Substitute for x in the 2nd equation.

You will end up with a quadratic equation that you should be
able to solve.