Answer:
y = - 140
Step-by-step 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
