Exercise 13 Page 243

When lines are parallel, they have the same slope. Let's consider the given equation. y=-5x+8 The slope of the line represented by the above equation is -5. Therefore, the slope of any parallel line will also be - 5. y=-5x+b To find the equation of a parallel line through the point 0, 2, we will substitute 0 and 2 for x and y, respectively, in the above formula.

y=-5x+b

SubstituteII

x= 0, y= 2

2=-5( 0)+b

ZeroPropMult

Zero Property of Multiplication

2=0+b

AddTerms

Add terms

2=b

RearrangeEqn

Rearrange equation

b=2

Now that we know the y-intercept is 2, we can write the equation of the parallel line through the given point. y=-5x+ 2