Create a matrix for this linear system, and find the solutions
(see attached image)

add -60 to 120 which will result in : 2x+3y=180

then subtract 2x: 3y=-2x+180

lastly, divide by 2: y= -2/3x+60

hope this is the answer you're looking for: )

graphs that are inverses of each other are graphs where their slopes are reciprocals of each other for example say you have an original equation of y=2x. the inverse of that graph would be y=-1/2(x). also when you see a graph where the original and the inverse is graphed the angle around intersection is 90 degrees.