Question

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​

Answer 1

a

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