z= 15/4 (which is also 3.75).
Work Step by Step
The quantity inside of the parenthesis is being multiplied by 5. Thus, we first divide by 5 to find that 2+4z=17. We now need to get the z alone. Thus, we cancel out the addition by subtracting 2 on both sides. This leaves us with the equation 4z=15. In order to cancel out multiplication, we use division, so we divide both sides by 4 to get that z=15/4. We plug 15/4 in for z and confirm that our answer is, indeed, correct.