How do you solve the system of equations by graphing #9x - 7y = -42# and #7y - 9x = 42# and then classify the system?
1 Answer
The solution for a system of linear equations is the point or points that they have in common. Because both equations represent the same line, they have all points in common, so there are an infinite number of solutions.
Explanation:
Solve system of linear equations by graphing:
The equations are the same.
Multiply Equation 2 by
Rearrange
To graph the lines, determine the x- and y-intercepts.
X-intercept: value of
Substitute
Divide both sides by
The x-intercept is
Y-intercept: value of
Substitute
Divide both sides by
The y-intercept is
Plot the intercepts and draw a straight line through both points.
The solution for a system of linear equations is the point or points that they have in common. Because both equations represent the same line, they have all points in common, so there are an infinite number of solutions.
graph{(9x-7y+42)(7y-9x-42)=0 [-10, 10, -5, 5]}