Question

HURRY!!! A direct variation goes through the points (1,4) and (2, 8) the constant variation is

Answer 1

Given points: (1,4) and (2,8)

Direct Variation:

The statement y varies directly as x, which means that when x increases, y increases by the same factor.

In other words we can say that, y and x always have the same ratio;

i.e,
`(y)/(x) = k` ; where k is the constant of variation.

or we can write this as :
`y=kx` ......[1]

Substitute the value of given points in [1];

For (1,4)

put x =1 and y = 4 we get;

`4= k(1)`

or

k =4

For(2,8)

put x = 2 and y= 8 in [1];

`8=k(2)`

Divide both sides by 2;

4 = k or k =4

As you can see that a direct variation goes through the points (1,4) and (2,8) , the constant variation in both cases is, k =4.