Exercise 62 Page 114

To find the equation of the line, we have to determine its slope m and y-intercept b. y=mx+b We have already been given the y-intercept as (0, - 3). Let's therefore substitute b= - 3 into the equation. y=mx-3 To complete the equation, we have to find the slope. Let's substitute the given points into the Slope Formula.

m=y_2-y_1/x_2-x_1

SubstitutePoints

Substitute ( 0,- 3) & ( - 9,- 9)

m=- 3-( - 9)/0-( - 9)

▼

Simplify right-hand side

SubNeg

a-(- b)=a+b

m=- 3+9/0+9

AddTerms

Add terms

m=6/9

ReduceFrac

a/b=.a /3./.b /3.

m=2/3

Now we have everything we need to complete the equation. y=2/3x-3