Question

If y varies directly as x, and y is 48 when x is 6, which expression can be used to find the value of y when x is 2?

Answer 1

If y varies directly as x,
y = kx


when y = 48, x = 6
plugging this in y = kx

48 = k*6
k = 48/6 = 8.

when x = 2,
y = kx = 8*2 = 16

so I think the expression you're looking for is:
y = 8*2 or y = (48/6)*2.

Answer 2

Find out the find the value of y when x is 2 .

To prove

As given

If y varies directly as x .

`y \propto x`

y = kx

Where k is the constant of proportionality.

y is 48 when x is 6,

48 = 6k

`k = (48)/(6)`

k = 8

Now calculate the value of y when x is 2 .

y = 8 × 2

y = 16

Therefore the value of y is 16 when x is 2 .