The equation would be (53.50-17.50)÷4 because we need to subtract the potting soil, and since there are 4 shrubs, then you need to divide to get the total of one shrub. It could also be (s=shrubs) 4s + 17.50 = 53.50 and then solve for s. Now, let's solve it. 53.50-17.50=36. Now, divide 36 by 4, to get 9. So, each shrub cost $9. Hope this helped!
