Exercise 2 Page 279

What do parallel lines have in common?

y=-2x+5

Practice makes perfect

When lines are parallel, they have the same slope. To help us identify the slope of this line, let's first convert it into slope-intercept form, y= mx+ b, where m is the slope and (0, b) is the y-intercept.

4x+2y=8

▼

Solve for y

SubEqn

LHS-4x=RHS-4x

2y=-4x+8

DivEqn

.LHS /2.=.RHS /2.

y=-4x+8/2

WriteSumFrac

Write as a sum of fractions

y=-4x/2+8/2

CalcQuot

Calculate quotient

y=- 2x+4

With this, we can more easily identify the slope m and y-intercept b.

y= - 2x+ 4 This means we can write a general equation in slope-intercept form for all lines parallel to the given equation. y= -2x+ b We are asked to write the equation of a line parallel to the given equation and has a y-intercept of 5. Therefore, we can conclude that the line given by the following equation is parallel to 4x+2y=8 has a y-intercept 5. y= -2x+ 5

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Exercises p.279

Exercise 2 Page 279

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