y=x and y= -2x +9 what's the answer if u have to graph ?

Question

How do u graph it and find the answer 

Answer 1

When you graph the equation y = x you have a y-intercept of 0 and a slope of 1.  Graph the point (0,0) and count a slope of 1 up and 1 right.  The line will go through the points{ ...(-1, -1), (0, 0), (1, 1)...}.  The graph of the equation y = -2x + 9 has a y-intercept of 9 and a slope of 2.  Graph the point (0, 9) and count a slope of 2 down and 1 right.  The line will go through the points {...(-1, 11), (0, 9), (1, 7),...}  The intersection of the two lines on your graph will be the point (3,3).

 

The check would be:  y = x, 3 = 3

                       and y = -2x + 9

                             3 = -2(3) + 9

                             3 = -6 + 9

                             3 = 3