Question

8. Y varies directly with x. If x= 4 and y = 12, find the constant of variation.

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Answer 1

Step-by-step explanation:

Since k is constant (the same for every point), we can find k when given any point by dividing the y-coordinate by the x-coordinate. For example, if y varies directly as x, and y = 6 when x = 2, the constant of variation is k = = 3. Thus, the equation describing this direct variation is y = 3x.

Answer 2

Answer:

the initial statement is

y

∝

x

to convert to an equation multiply by k the constant

of variation

⇒

y

=

k

x

to find k use the given condition

y

=

12

when

x

=

4

y

=

k

x

⇒

k

=

y

x

=

12

4

=

3

⇒

equation is

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

∣

∣

∣

2

2

y

=

3

x

2

2

∣

∣

∣

−−−−−−−−−−−