How can i determine the range of the function ?

Solve the system of equations y= 3/2 - 1, -x+ y =-3

Aprobability experiment is conducted in which the sample space of the experiment is s={7,8,9,10,11,12,13,14,15,16,17,18}, event f={7,8,9,10,11,12}, and event g={11,12,13,14}. assume that each outcome is equally likely. list the outcomes in f or g. find p(f or g) by counting the number of outcomes in f or g. determine p(f or g) using the general addition rule.

Given: m zade = 60° and m2cdf = (3x + 15) prove: x = 15