Question

If y varies directly as x and y = 6 when x = 18, then find x when y = 10.

Answer 1

ok... so direct variation means the equation is in the form

y = kx

you need to find k, knowing when x = 18, y = 6

so whats the value of k...?

Answer 2

and can you please check the question says y = 6 when x = 18... and not the other way round.

Answer 3

1/3? @campbell_st

Answer 4

thats correct so the equation is

y = 1/3 x

so now subtitute y = 10 to find x

Answer 5

So the answer is 10/3?

Answer 6

no its

10 = 1/3 x

so try again

Answer 7

just multiply both sides of the equation to find x

Answer 8

30!

Answer 9

yes... well done

Answer 10

@campbell_st Thank you so much!

Answer 11

@campbell_st I have one more question.

Question: Table represents direct variation

x: 1,2,3,4
y: 12,6,4,3

This is false right?

Answer 12

ok... so again

y = kx

use the 1st result to find k

12 = k* 1

so k = 12

then the equation is

y = 12x

is that true for every pair

try x = 2 what should you get and compare it to the y value in the table

then x = 3 what should you get

Answer 13

It is false ?

Answer 14

opps... yes you are correct

Answer 15

Okay! Thank you very much, again!