Question

suppose that y varies jointly with x and z. Find your when x=3 and z=5 , given that y=72 when x=6 and z=4

Answer 1

y α xz

y = kxz             y = 72, when x = 6, and z = 4

72 = k*6*4

72 = k*24

24k = 72

k = 72/24

k = 3.

y = kxz    

y = 3xz    

Finding y, when x = 3, z = 5.

y = 3xz

y = 3*3*5

y = 45