SOLUTION: Solve and check a) 2log(x-1) = 2+ log 100

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Question 742189: Solve and check
a) 2log(x-1) = 2+ log 100

Found 3 solutions by josgarithmetic, lwsshak3, MathTherapy:
Answer by josgarithmetic(39838) About Me  (Show Source):
You can put this solution on YOUR website!
2*log(x-1)=2+log(100)
2log(x-1)-log(100)=2
log(x-1)^2-log(100)=2
log((1/100)(x-1)^2)=2

What you do next depends on what the base is. Assuming you are using some base, b, you would transform:
b%5E2=%281%2F100%29%2A%28x-1%29%5E2
Also, looking carefully at the factor on the right side,
b%5E2=%28%28x-1%29%2F10%29%5E2
Seeing that, the base must be equal to the expression shown in the same position on the rightside:
b=%28x-1%29%2F10.

From this, 10b=x-1
highlight%28x=10b%2B1%29 You need to know the value of b in order to find anything further.

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Solve and check
a) 2log(x-1) = 2+ log 100
2log(x-1) = 2+2
2log(x-1) = 4
log(x-1) =2=log100
x-1=100)
x=101
check:
2log(x-1)=2log(100)=2*2=4
2+log 100=2+2=4

Answer by MathTherapy(10858) About Me  (Show Source):
You can put this solution on YOUR website!
Solve and check
a) 2log(x-1) = 2+ log 100
*************************
The response from @josgarithmetic(39831), while correct, is confusing, in this author's opinion. Whenever one sees a log argument without a base,
it's widely known that that base is 10, since that's the base/number system we all work in. This is just the same as x. It's known that this is actually
1x, but it's not written like that, just x. Also, x is actually x%5E1, but again, it's not written as such, just x. So, why confuse a person by working the
problem without a base, just because a base wasn't stated? That base, as stated before, is OBVIOUSLY no other than 10. 

          2 log(x - 1) = 2 + log (100)
          2 log(x - 1) = 2 + 2 ---- log (100) = 2
          2 log(x - 1) = 4
%282%28log%28%28x+-+1%29%29%29%29%2F2+=+4%2F2 ----- Dividing each side by 2 
            log (x - 1) = 2
                     x+-+1+=+10%5E2 ---- Converting to EXPONENTIAL form
                     x - 1 = 100
                           x = 100 + 1 = 101

You can do the CHECK!!