First we make our formula: 5(t+15.25)+15t=211.25. (I use the same letter for both variables, but you have to make sure that whatever makes them different is in the formula) Then you work it like normal: 20t=135, T=6.75 so 1 shrub costs $6.75 Then substitute the answer in: 5(6.75+15.25)+15(6.75)=211.75 and check it. 1 tree is $110 :) hope this helps :)
