Question

find the point of intersection of the graphs iii.y=x+9 y=7-3x iv. y=2x-6 y=-2

Answer 1

iii. Set the equations equal to each other (explanation: a point of intersection of the 2 equations would have the same y-value, and both equations are currently solved for y). Then solve the new equation, x+9 = 7-3x for x. Plug the solution for x back in one of the original equations for y, and you'll have your point (x,y)

Answer 2

iv. Same concept as above. Since both equations are solved for y, you can set them equal to each other and solve for x then back for y.