Exercise 7 Page 175

We can find the line that passes through the given points by using the slope-intercept form of equation. y= mx+ b For an equation in this form, m is the slope and b is the y-intercept. Let's use the given points to calculate m. We will start by substituting the points into the Slope Formula.

m = y_2-y_1/x_2-x_1

SubstitutePoints

Substitute ( 0,- 5) & ( 2,- 5)

m=- 5-( - 5)/2- 0

▼

Simplify right-hand side

SubNeg

a-(- b)=a+b

m=- 5+5/2-0

AddSubTerms

Add and subtract terms

m=0/2

0/a=0

m= 0

A slope of 0 means that this function is constant. Now that we know the slope, we can write a partial version of the equation. y= 0 x+ b To complete the equation, we also need to substitute the y-intercept, b. We can see that one of our given points, (0, - 5), lies on the y-axis. Since the line crosses the y-axis at this point, we know the y-intercept and can complete the equation. y= 0x+( - 5) ⇔ y=- 5