Idk if she's too young to learn cross multiply, but this is an easier method.
Multiply everything by 4 which cancels out the 4 on the left side.
36z-16/5 <= 7z + 2
Now multiply everything by 5, cancelling out the right side 5.
36z-16 <= 35z + 10
Solve the equation normally
z-16<=10
z<=36