Irene R. answered 04/02/20
BS in Mechanical Engineering and Certified math teacher for 13 years
Hi Michelle,
Parallel lines have the same slope. In the slope-intercept form, y = mx + b, the variable m represents the slope and the variable b represents the y-intercept.
For the equation, y = -9 x + 5, the slope is -9. Therefore, the slope of any parallel line will also be -9.
Next, substitute the x and y coordinates for the point provided (5,-7) to determine the y-intercept of the new line:
y = mx + b
y = -9x + b
-7 = -9 •5 + b
-7 = -45 + b
-7 + 45 = -45 + b + 45
38 = b
The equation of the new line in slope-intercept form will be:
y = -9x + 38
Let me know if you have other questions or need any lessons Michelle. Would be happy to help!