Let's factorise it :

![\: {\qquad \dashrightarrow \sf {x}^{3} (x + 3) + [-5(x + 3)] }](https://tex.z-dn.net/?f=%5C%3A%20%7B%5Cqquad%20%20%5Cdashrightarrow%20%5Csf%20%20%20%20%7Bx%7D%5E%7B3%7D%20%28x%20%2B%203%29%20%2B%20%5B-5%28x%20%2B%203%29%5D%20%20%7D)
Using Distributive property we get :



⠀
Therefore,

I believe it is -8y + 5x - 3
If it's add you subtract if it's subtract you add
If we refer to the longest side as x and the shortest side as y and the medium side as z then we come up with this formation:
x+y+z= 22
y is shorter than x by 5 inches so y= x-5
z is longer than y by 2 inches therefore z= x-5 +2
therefore:
x+(x-5)+(x-5+2)=22
x+x-5+x-5+2=22
3x-8=22
3x= 22-8
3x=14
x=

replace x in y and z in previous formations
The answer is c = .6x + 5
In order to find the equation, note that the price per pound is contingent upon the weight in x. Therefore, we can multiply the two together.
We also need to add the constant, which is 5.