Question

if z varies jointly with x and y, and z=24 when x=2 and y=3, what is the value of z when x=4 and y=2.​

Answer 1

Answer:

It is given that z varies jointly as x and the square root of y if z=6 when x=3 and y=16, therefore,

z=kx

y

⇒6=k×3×

16

⇒6=k×3×4

⇒12k=6

⇒k=

12

6

=

2

1

Thus, the general equation is z=

2

1

x

y

.

Since x=7 and y=4, therefore,

z=

2

1

x

y

=

2

1

×7×

4

=

2

1

×7×2=7

Hence, z=7 cm when x=7 and y=4.