20x+35y=150
A) Since Lyla has $150 to buy shrubs, and the small ones cost $20, and the large ones $35, we can write out the following equation
Note that, we need to find the number of shrubs altogether in order to set another equation and solve this linear system.
In addition to this, this equation relates the cost of each shrub and the total expenditure.
Thus, the equation for Part A is 20x+35y=150