How do i work out x ?

3 times 2 to the power of x-1 =24
i dont understand how to work out x

1 Answer
Aug 6, 2017

x=4

Explanation:

"what we have is "

3xx2^(x-1)=24

"isolate "2^(x-1)" by dividing both sides by 3"

rArrcancel(3)^1/cancel(3)^1xx2^(x-1)=24/3

rArr2^(x-1)=8

• " note that "8=2^3

rArr2^(x-1)=2^3

"since the bases are both 2 we can equate the exponents"

rArrx-1=3

"adding 1 to both sides gives"

x=4

color(blue)"As a check"

3xx2^((4-1))=3xx2^3=3xx8=24larr" True"

rArrx=4" is the solution"