Lesson 11: Connecting Equations to Graphs (Part 2)

Question

If we graph the equation, what is the slope of the graph?

Where does the graph intersects the -axis?

Where does the graph intersects the x-axis?

Answer 1

First, this can be manipulated to find the slope and y intercept

y=mx+b, m is the slope and b is the y intercept

1.5x+4.5y=18 Subtract 1.5 x from both sides of the equation

4.5y=-1.5x+18 Divide both sides of the equation by 4.5

4.5y/4.5=-1.5x/4.5+18/4.5

y=-1/3x+4

The slope is -1/3

The y intercept is (0,4)

To find the x intercept, yet y=0 and solve.

1.5x+4.5y=18

1.5x+4.5(0)=18

1.5x=18 Divide both sides of the equation by 1.5

1.5x/1.5=18/1.5

x=12

The x intercept is (12,0)