Question

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

Answer 1

Answer:

$y=3x$

y=57, when x is 19.

Step-by-step 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,

$15=k*5$

$k=\frac{15}{5}$

$k=3$

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

Now let us find y, when x is 19.

$y=3*19$

$y=57$

Therefore, y equals 57, when x is 19.