Question

Suppose a and b vary inversely, and b = 8 when a = 6. Write a function that models the variation and find b when a = 30.

Answer 1

for inverse variation , the product of variables = constant.
so here ab = k (a constant)
so, can you find 'k' given that b=8,a=6 from ab=k ?

Answer 2

Alright How would i start my problem ?

Answer 3

i gave you start only.

For, inverse variation. ab = k
put a=6,b=8, then
k=.... ?

Answer 4

Oh okay. Hold on let me work it out

Answer 5

do i do it like this (6)(8)=k ?

Answer 6

yes, correct!
so, k=... ?

Answer 7

48

Answer 8

correct :)
so, your function is ab =48 .

for 2nd part , just put a=30 in that function and find b.....

Answer 9

when you mean put a for 30 isnt 6 already a unless i replace it

Answer 10

yes, 8 and 6 are now useless.
you have ab = 48
put a= 30 , what you get ?

Answer 11

(30)(8) = 240

Answer 12

8 is useless, keep b as b only
so, 30 b=48
got this ?
to get b now, divide both sides by 30..

Answer 13

got that. Did what both sides by 30 ?

Answer 14

divide

Answer 15

30/48 ?

Answer 16

30 b/30 = 48/30

Answer 17

48/30 = 1.6

Answer 18

so, b= 8/5 =1.6

Answer 19

how you get b= 8/5 i thought it was 1/6

Answer 20

@hartnn

Answer 21

48 = 6*8
30 =6*5
48/30 = 6*8 /6*5 = 8/5

Answer 22

Oh okay cool. Is this all for part 2 ? And is this all for my answer as well part 1 & 2

Answer 23

yes, thats it...
ab = 48
b= 8/5

Answer 24

Thank you so much : )

Answer 25

welcome ^_^