Q Apply
Do the data in each table represent a direct variation or an inverse variation?
Write an equation to model the data in each table.
25.Se e Pr o b l e m 4.—— BB an
2 1 4 15 -3 -2 4(^5) 2.5 6 10 9 8
(^84106126)
Tell whether each situation represents a direct variation or an inverse variation. ^ See Problem 5.
Explain your reasoning.
- You buy som e chicken for $1.79/lb.
- An 8-slice pizza is shared equally by a group of friends.
- You find th e length an d w idth of several rectangles. Each has an area of 24 cm2.
Suppose y varies inversely with x. Find the constant of variation k for each
inverse variation. Then write an equation for the inverse variation.- y = - 8 w h e n x = —32 32. x = |w h e n y = 5 33. y = 25 w h e n x = 0.04
Each pair of points is on the graph of an inverse variation. Find the
missing value.- (3, 5) an d ( l,y ) 35. (2.5, 4) a n d (x, 2) 36. (x, 2 j an d ( 3, 4 )
Measurement Does each formula represent a direct variation or an inverse
variation? Explain your reasoning.- th e p erim e te r P of an equilateral triangle w ith side length s: P = 3s
- th e tim e t to travel 150 m i at a rate of r m i/h : t -
- th e circum ference C of a circle w ith radius r. C = 2 irr
(^150) r
- Think About a Plan S uppose 4 p eople can p a in t a h o u se if they w ork 3 days each.
How long w ould it take a crew of 5 p eo p le to p a in t th e house?- Can you d eterm in e w h e th e r this situation represents a direct variation or an
inverse variation? - How can you write an eq u a tio n th a t will help you
solve th e problem?
- Can you d eterm in e w h e th e r this situation represents a direct variation or an
- Writing Explain how th e variable y changes in each
situation.
a. y varies directly w ith x. The value of x is doubled.
b. y varies inversely w ith x. The value of x is doubled. - Surveying Both of the two rectangular building
lots show n at th e right have th e sam e area. W rite an
equ atio n to find th e length of th e seco n d lot.
Po w erAlg eb ra.com | L e s s o n 1 1 - 6 Inverse Variat io n 703