The area of a rectangle varies jointly as the length and the width, and whose A = 72 sq. cm when l = 3 cm and w = 2 cm. What is the constant of variation (k)? a. 12
b. 10
c. 8
d. 14

a

Step-by-step explanation:

Given A varies jointly as l and w then the equation relating them is

A = klw ← k is the constant of variation

To find k use the condition A = 72 when l = 3 and w = 2 , then

72 = k × 3 × 2 = 6k ( divide both sides by 6 )

12 = k

easy its decreasing

step-by-step explanation:

because its top point is at the to of the graph on the left side (atleast from the veiw i see it) now if that top point wast in the lower part of the graph it would be increasing hope this have a nice day

answer:

total cost for tiles and paints is $924.  

step-by-step explanation:

we have been given that a community hall is in the shape of a cuboid. the hall is 40m long 15m high and 3m wide.

the paint will be required for 4 walls and ceiling.

let us find area of walls and ceiling.

therefore, the area of walls and ceiling is 1410 square meters.

given: cost for 10 litre of paint is $10 and 10 litre paint covers 25 square meter. therefore,

therefore, the total painting cost is $564.

tiles will be required for floor. let us find the area of floor.

given: 1m squared floor tiles costs $3. so,

therefore, the total tiles cost is $360.

now let us find combined total cost of tiles and paint.

therefore, the combined total cost of tiles and paint is $924.