Question

If y varies jointly as x and z and inversely as the square of w, and y =3 when x=3, z=10 and w=2, then y=4 when x=4 z=20 w=4

Answer 1

Answer:

0.4 ; 0.8

Step-by-step explanation:

Given that :

y varies jointly as x and z and inversely as the square of w

y ∝ xz ∝ 1/w^2

y = kxz/w^2 - - - - (1)

Given that y =3 when x=3, z=10, w=2

Inputting the values into (1)

3 = (k*3*10) / 2^2

3 = 30 × k / 4

k × 30 = 3 × 4

k × 30 = 12

k = 12/30

k = 0.4

B.) Given that ;

y=4 when x=4 z=20 w=4

Input values into (1)

y = kxz/w^2

4 = ( k * 4 * 20) / 4^2

4 = (k * 80) / 16

k * 80 = 16 * 4

k * 80 = 64

k = 64 / 80

k = 0.8