Question

If y varies inversely as x and y is 1.5 when x is 8, what is y when x is 2? a. 0.09 b. 12 c. 6 d. 0.38  

Answer 1

y varies inversely with x.
∴ y α 1/x
Let k be the proportionality constant.
∴ y = k/x ------ 1.
y is 1.5 when x is 8.
∴ 1.5 = k/8
∴ k = 1.5×8 = 12
Plug x = 2 and k = 12 in 1 to get y.

y = 12/2 = 6

Answer 2

⓵
If it’s inversely proportionate, multiplying × by ỿ has to always give you the same result!

So × • ỿ = ?

8 • 1,5 = 12

⓶
Now that you know what your answer should be, look at the multiple choices.

If × equals 2 and multiplying × by ỿ has to give you 12, what should ỿ be?


× • ỿ = 12

2 • ỿ = 12

All you need to do is simplify the left side in order to isolate the ỿ.

2 • ỿ = 12
÷2 ÷2

Ỿ = 6

So the answer is : ỿ is 6 when × is 2!

I hope this helps! ☻