The first line in a system of linear equations has a slope of 3 and passes through the point (-1 , -8). The second line passes through the points (-6 , 3) and (10 , -1).
The equation of the first line can be written in point-slope form as .. y = 3(x +1) -8 or .. 3x -y = 5
The equation of the second line can be written in 2-point form as .. y = (-1-3)/(10-(-6))*(x +6) +3 .. y = (-1/4)(x +6) +3 or .. x +4y = 6
A graph shows the solution to this system is (x, y) = (2, 1).
_____ The second equation can be used to write an expression for x: .. x = 6 -4y This can be substituted into the first equation. .. 3(6 -4y) -y = 5 .. 18 -13y = 5 . . . . . . . collect terms .. 13 = 13y . . . . . . . . . add 13y-5 .. 1 = y . . . . . . . . . . . . divide by 13 From the above equation for x .. x = 6 -4*1 = 2
