Thhe easiest way would be to solve for y first
4x=3y-7
add 7
4x+7=3y
divide both sides by 3
(4x+7)/3=y
try each
x=4
(4(4)+7)/3=y
(16+7)/3=y
(23)/3=y
7 and 2/3=y
(4,7.66666)
x=5
(4(5)+7)/3=y
(20+7)/3=y
(27)/3=y
9=y
(5,9)
x=6
(4(6)+7)/3=y
(24+7)/3=y
(31)/3=y
10 and 1/3=y
(6,10.333)
(4,7.66666)
(5,9)
(6,10.333)
when x=4, y=7 and 2/3
when x=5, y=9
when x=6, y=10 and 1/3
7
Because 5-2 is seven so x =7
It should be for 5 hours if $30 is what they started with
Answer: r = 1.69 inches
h = 2.15 inches
Step-by-step explanation: Volume of a solid is the amount of space contained within a solid.
Volume of a cone is directly proportional to radius and height:

They want the cones to hold the same volume of 9 cubic inches.
If height is 3:



r = 1.69 inches
When height is 3, radius is 1.69 inches for a cone to have 9 cubic inches of volume.
If radius is 2:


h = 2.15 inches
If radius is 2 inches, height of the cone is 2.15 inches.