Parallel and Perpendicular Lines

Identify the slope of y = -1/3x + 8

• 3

• -3

• -1/3

• 1/3

Answer explanation

When looking at an equation in slope intercept form ( y = mx+b), the m value represents your slope.

Tags

CCSS.8.EE.B.5

Identify if the following lines are parallel?

y - 3 = -2(x - 3) and y = 2x - 7

• Yes

• No

• I 'unno

Answer explanation

Despite both equations being in different forms of a line (one point slope and one slope intercept), both have an easy to detect slope (the value next to the x) and since they are not the same, they are not parallel.

Tags

CCSS.4.G.A.1

CCSS.HSG.CO.A.1

Which of the following lines are parallel to the following equation: f(x) = 9x - 2

• y = 9x

• y = 3 -9x

• y = 1/9x - 8

• y = 2 - 1/9x

Answer explanation

Parallel lines have the same slope!

Please create a line that is parallel and a line that is perpendicular to y = 3x + 2.

If Harris traveled from his home (-3,-4) to the grocery store (-1,2), and his friend Susie is at a location perpendicular to the grocery store, which of the following lines would represent the path to her home?

(The values of the axis are moving by 1)

• y = -3x + 5

• y = 3x -5

• y = 1/3x -5

• y = -1/3x + 5

Answer explanation

Perpendicular lines have a slope that is opposite and reciprocal (flipped fraction)

Identify the equations that are parallel

a)      y = 2x + 5

b)      y = -x + 3

c)      y = x – 4

d)      y = 1/3x – 7

e)      y = 2x - 1

f)       y = -1/3x + 1

• A and F

• B and C

• A and E

• D and F

Answer explanation

Parallel lines have the same slope!

Identify the equations that are perpendicular

a)      y = 2x + 5

b)      y = -x + 3

c)      y = x – 4

d)      y = 1/3x – 7

e)      y = 2x - 1

f)       y = -1/3x + 1

• A and F

• B and C

• A and E

• D and F

Answer explanation

Perpendicular slopes are opposite and reciprocal (flipped fraction)

Identify the equations that are intersecting

a)      y = 2x + 5

b)      y = -x + 3

c)      y = x – 4

d)      y = 1/3x – 7

e)      y = 2x - 1

f)       y = -1/3x + 1

• A and F

• B and C

• A and E

• D and F

Answer explanation

Because A and E are the only pair of parallel lines, all the other lines will intersect with their pair.

Tags

CCSS.8.EE.C.8B

CCSS.HSA.REI.C.6

1)      Two competing grocery stores compared their profits and found that their sales were working in a perpendicular trend, with one earning profit and one losing. One grocery store was gaining profit that year using the trend: 2x - y = -2. Determine which of the following equations could represent the competing store.

• y = -2x + 1

• y = 2x + 10

• y = -1/2x + 4

• y = 1/2x + 4

Answer explanation

The original equation is written in standard form. Once that equation is rewritten, you will be able to identify the slope and then write the perpendicular (opposite/reciprocal) slope

Tags

CCSS.8.EE.C.8C

1)      Farmer Jack planted 10 rows of strawberries and 8 rows of blueberries during the past year. When they plotted the growth rate of the two crops to compare on a graph, they found that the two grew at the same rate. Which of the following equations could have been the graphed lines?

• y = 2x +10 and y = 2x + 8

• y = -2x +10 and y = 2x + 8

• y = -2x + 10, y = -1/2x +8

• y = 2x +10 and y = 1/2x +8

Tags

CCSS.8.EE.C.8C