You can solve the pair of equations graphically by finding where the two lines intersect/meet. The point where they intersect is the solution to both of the equations.
Slope-intercept form: y = mx + b
(m is the slope, b is the y-intercept, or the point where x = 0 ---> (0 , y))
y = 7x - 9
m = 7
y-intercept = -9 -----> (0, -9)
y = 3x - 1
m = 3
y-intercept = -1 ------> (0, -1)
I'm not really sure what the last sentence of the question is asking, so you could clarify the question if you need help
