1.
Suppose y varies directly with
x
and
y
= 14 when
x
= 3.5. Write an equation relating
x
and
y
.
A.
B.
y
= 4
x
C.
D.
y
= -4
x
Hint
2.
The direct variation equation
y
= .1
x
gives the price
y
for
x
minutes of a long distance calling plan. Use the equation to find the cost for a phone call that is 32.5 minutes long.
A.
$3.28
B.
$3.30
C.
$3.25
D.
$3.20
Hint
3.
Suppose
y
varies directly with
x
and
when
Write an equation relating
x
and
y
.
A.
B.
C.
D.
Hint
4.
The direct variation equation
y
= 19.99
x
gives the total cost
y
of
x
DVDs at a store. Find the total cost of 5 DVDs.
A.
$119.94
B.
$99.80
C.
$99.95
D.
$94.95
Hint
5.
At a gas station, 15 gallons of gas has a price of $17.55 and 18 gallons of gas has a price of $21.06. Write a direct variation equation that relates the cost
y
of any number of gallons of gas
x
.
A.
y
= 1.15
x
B.
y
= 1.2
x
C.
y
= 1.07
x
D.
y
= 1.17
x
Hint