Find an equation of variation where y varies directly as x and y = 15 when x = 5, find y when x is 19.

Question

asked Jan 20, 2019 8.0k views

1 Answer

Sinstein · Answer 1 · 2019-01-24T04:53:33+0000

Answer:

y=3x

y=57, when x is 19.

Explanation:

We are asked to write an equation of variation where y varies directly as x.

Since we know that a directly proportional equation is in form:
y=kx , where k is the constant of proportionality.

Upon substituting x=5 and y= 15 in our equation of variation we will get,

15=k*5

k=(15)/(5)

k=3

Upon substituting k=3 in the standard equation of variation we will get our desired equation of variation as:
.

Now let us find y, when x is 19.

y=3*19

y=57

Therefore, y equals 57, when x is 19.