GCA, Direct and inverse proportion

If variables x and y are in direct proportion and k is a constant, then a valid equation for these variables is

• y + x = k

• y - x = k

• xy = k

• $\frac{y}{x}\ =\ k$

g is directly proportional to b

Given g=20 when b=4.

Find g when b=7

• 35

• 5

• 15

• 23

The amount of money earned on a job is directly proportional to the number of hours worked. If $70.00 is earned in 5 hours, how much money is earned in 22 hours of work?

• $2

• $308

• $21.57

• $25.6

What type of variation does this scenario represent?

The length of time you charge your cell phone

and the battery power

• direct variation

• inverse variation

• joint variation

• none of these

What type of variation does this scenario represent?

The outside temperature

and the number of layers of clothes you need to wear outside to feel comfortable

• direct variation

• inverse variation

• joint variation

• None of these

The width of a rectangle varies inversely with its length. if the width is 4 when the length is 18, find the width when the length is 8.

• 72

• 36

• 9

• 2

The number of pencils sold varies directly as the cost. If 5 pencils cost $0.45, find the cost of 7 pencils.

• Inverse Variation

• Direct Variation

t is inversely proportional to v

t=2 when v=6

Find the equation for t and v

• t = ¹²/_v

• t = ¹/₃ v

• t = ³/_v

• t = 12v

Name the constant of proportionality.

• 20
• 40
• 16
• 35

Tags

CCSS.8.EE.B.5

CCSS.8.EE.B.6

CCSS.8.F.B.4

Every 30 seconds, you can text 35 words. How many words can you type in an hour? 

• 2,300
• 4,200
• 540
• 1,800

Tags

CCSS.8.EE.B.5

CCSS.8.F.B.4