Question

Suppose y varies jointly as x & z. If y = -180 when z = 15and x = -3,then find y when x = 7 and z = -5. 1 point

Answer 1

y = - 140

Explanation:

The statement

y varies jointly as x & z is written as

y = kxz

to find y when x = 7 and z = -5 we must first find the relationship between the variables

when y = - 180

z = 15

x = - 3

- 180 = k(15)(-3)

-180 = - 45k

Divide both sides by - 45

k = 4

The formula for the variation is

y = 4xz

when

x = 7

z = -5

y = 4(7)(-5)

y = 4(-35)

y = - 140

Hope this helps you