First you have to find the slope with the equation y2 - y1 / x2 - x1 , then once you have found the slope (slope = -2) you simply plug it into the point slope formula. y-0 = -2(x-5) solving it algebraically you should arrive at Y=-2x+10. (the 5 and 0 were plugged in are two of the X and Y points of the line which is why we plugged them into the X and Y values of the equation)
96+80= (100-4)+(100-20)
= 200-24
=174
The +2 would cause a shift of up two on the y-axis. the 2 infront of the x, would cause the graph to narrow. using the point 0 f(x) would be 2 or (0,0) and on g(x) it would be (0,2) using x=3, you would have (3,3) and (3,8)