I don't know how to do this and I need help

Question

Okay, so now all in all we have built our farm and found what to price each of our crops at. Now let’s find what amount of each crop to grow and find our profits. Getting right into it, we have the following cost equations: CW = $20.00 * W + $50.00 CG = $10.00 * G + $40.00 Where CW is the total cost of planting and growing Watermelons, CG is the total cost of planting and growing Grapes, W is the area of Watermelons planted, and G is the area of Grapes planted. Now that we know our cost, we can finally find our profits. Profit is equal to the price per unit area, multiplied by the area sold, subtracted by the total cost planting and growing them, or, Profit = Price * Area - Cost But at this point, we still don’t know the area of each crop in our field. But we do know a couple of things to figure it out. We know the total area of our farm, found in the first part. Which we can say is, Area = G + W And we were also only given $1590 to plant the crops. So, $1590.00= CW+CG I’ll help you simplify this a bit, $1590.00=$20.00*W+$50.00+$10.00*G+$40.00 $1590.00=$20.00*W+$10.00*G+$90.00 So now we have enough information to solve for the areas of Watermelons and Grapes in your field. Here’s some room to do that. Hint: Use either substitution, or graph the two equations to find an intersection.

Now that we know the area of each to be grown, we can finally stick those values into our Profit equation for W and G respectively

Answer 1

This is a system of two linear equations

Eq1: A = G + W

Eq 2: 1590.00=20W + 10G + 90

So solve for G and W, you will need to use the value of A you found in the first part (not shared here). But even without the value we have enough information to solve for A.

If you have A, the problem is simple to solve by substitution.

Step 1 - rearrange Eq1 into G = A - W

Substitute the two versions of Eq 1 into Eq 2:

1590 = 20W+ 10 (A - W) + 90

1590 = 20W + 10 A - 10W + 90

1590 = 10W +10A + 90

1500 = 10W + 10A

1500-10A = 10W

150 - A = W

From the boldface solution above, substituting the value of A which you did not provide, we can easily determine W and then use the value of W to solve for G, since W + G = A.