Question

Y varies directly as x. Y=42 when x=6. Find the value of y when x =15.

Answer 1

Answer:

y=120

Step-by-step explanation:

Y varies directly as x is written as

$y \alpha x$

introducing a constant

y=kx

from the question, when y=48, x=6

substitute it in the formula

48=6k

making k the subject by dividing through by 6

$\frac{48}{6} = \frac{6k}{6}$

k=48/6

k=8

put the value of k in the expression y=kx

y=8x

from the question,the value of y when x=15 is given by

y=8×15

y=120.