Question

Find the value of k.

Answer 1

The value of k where?

Answer 2

From the attached picture @mightyrecords

Answer 3

What i have done is swapped the 3^k with the 42(3^3/2). so i got something like
3^7/2+3^5/2+3^3/2-3^k=42(3^3/2). are we okay upto that point

Answer 4

maths made simpler. wish i had that application for writing answers with a stylus. pc's suck in maths!

Answer 5

ktnguyen, the 42u in the first equations has power 3

Answer 6

The answer is given as 4.5....

Answer 7

Please help... :/

Answer 8

I got it :)

Answer 9

please show. are you still using logs and indices?

Answer 10

\[(\sqrt(3))^7+(\sqrt(3))^5+(\sqrt(3))^3+42(\sqrt 3) \]
You can solve this part I guess,you will get around 140.3 u can round it off to 140

Answer 11

now 140 is 3 to the power what?
we know
3^2=9
3^3=27
3^4=81
3^5=243
oops,so 140 lies somewhere betwen 4 and 5 so its 4.5
just a layman basic maths :)

Answer 12

If you use logs from DLS's answer you will get that exact answer 4.5

Answer 13

it will be something like (log 140.3)/log3=k

Answer 14

@BelleFlower ?