SOLUTION: for the data in the table tell whether y varies directly with x if it does write an equation for the direct variation x y 0 0 1 -2.5 2 -5 3 -7.5

Algebra ->  Graphs -> SOLUTION: for the data in the table tell whether y varies directly with x if it does write an equation for the direct variation x y 0 0 1 -2.5 2 -5 3 -7.5      Log On


   

Question 370074: for the data in the table tell whether y varies directly with x if it does write an equation for the direct variation
x y
0 0
1 -2.5
2 -5
3 -7.5
Found 3 solutions by mananth, ewatrrr, stanbon:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
x y
0 0
1 -2.5
2 -5
3 -7.5
..
y = 2.5x is the equation

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

*Note: when x = 0, then y = 0

Letting k represent the constant to see if y varies directly with x:

y = k*x  

using Pt (1,(-5/2)) to solve for k

(-5/2) = k*1

(-5/2) = k

checking k against the remaining data

-5 = (-5/2)*2

-7.5 = -7 1/2 = (-15/2)= (-5/2)*3

y = (-5/2)x      is the equation for this direct variation

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
for the data in the table tell whether y varies directly with x if it does write an equation for the direct variation
x y
0 0
1 -2.5
2 -5
3 -7.5
-------------
(0,0) tells you the y-intercept is 0
---
Since y decreases by 2.5 for each x-increase of one
the slope is -2.5
----
Equation:
y = -2.5x
==================
The variation is direct.
All linear function have direct variation.
------------------
Cheers,
Stan H.