Respuesta :
Answer: the value of y is 180
Step-by-step explanation:
If y varies directly as x, then as y increases,x increases and as y decreases, x decreases.
We would introduce a constant of proportionality, k. Therefore,
y = kx
When y = - 18, x = - 2
Therefore,
- 18 = - 2 × k
Dividing the left hand side and the right hand side of the equation by
- 2, it becomes
- 2k/ -2 = - 18/-2
k = 9
The expression becomes
y = 9x
Therefore, when x = 20,
y = 9 × 20 = 180
Yo sup??
since y varies directly with x we can say
y=kx
at y=-18, x=-2 then
-18=k*(-2)
k=9
therefore
y=9x
at x=20
y=9*20
=180
Hope this helps.