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Question 57306This question is from textbook
: The ordered pairs are for the same direct variation. Find each missing value.
(-1,2) and (4,y)
How would you do that?? would y be 7 because the difference between -1 and 2 is 3, and 4+3=7???
This question is from textbook
Answer by funmath(2933)   (Show Source):
You can put this solution on YOUR website! The ordered pairs are for the same direct variation. Find each missing value.
(-1,2) and (4,y)
If y varies directly as x, then y=kx. k is the constant of variation.
We can use the first point to find out what k is so that we can solve for y in the second point.
(x,y)=(-1,2) and y=kx substitute the x and y in and solve for k.
2=k(-1)
2=-k
-(2)=-(-k)
-2=k
Therefore our equation is: y=-2x
we can use this to solve for y in the second point.
(x,y)=(4,y) and y=-2x substitute 4 in for x and solve for y.
y=-2(4)
y=-8
Happy Calculating!!!
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