To simplify this equation, we have to combine like terms and even the equation.
First, combine the like terms.
180 = 2z + 15 + 3z - 4
180 = 5z + 15 - 4
180 = 5z + 11
Awesome! Now, we need to do is subtract 11 from each side...as so:
180 - 11 = 5z + 11 - 11
180 - 11 = 5z
169 = 5z
Great! All that is left to simplify is the 5z, and we do this by dividing 5 from 169 and from 5z. (This leaves z alone on one side of the equation.)
169 / 5 = 5z / 5
169 / 5 = z
33.8 = z
To check our work, we can replace z with 33.8 in the original equation:
180 = 2(33.8) + 15 + 3(33.8) - 4
180 = 67.6 + 15 + 101.4 - 4
180 = 82.6 + 101.4 - 4
180 = 184 - 4
180 = 180!
Our solution is correct! Hope I could help you out! If my math is wrong, or isn't the answer you are looking for, please let me know! Have a good one!