SOLUTION: I've forgotten how to solve simple logorithims.. haha 3. Find all real solutions to the following: a) log2(x 􀀀 2) + log2(x + 1) = log2 10

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: I've forgotten how to solve simple logorithims.. haha 3. Find all real solutions to the following: a) log2(x 􀀀 2) + log2(x + 1) = log2 10      Log On


   

Question 581755: I've forgotten how to solve simple logorithims.. haha
3. Find all real solutions to the following:
a) log2(x 􀀀 2) + log2(x + 1) = log2 10
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Use the general rule
+log%28a%29+%2B+log%28b%29+=+log%28a%2Ab%29+
+log%282%2Cx-2%29+%2B+log%282%2Cx%2B1%29+=+log%282%2C10%29+
+log%282%2C%28x-2%29%2F%28x%2B1%29%29+=+log%282%2C10%29+
+%28x-2%29%2F%28x%2B1%29+=+10+
+x+-+2+=+10%2A%28+x+%2B+1+%29+
+x+-+2+=+10x+%2B+10+
+9x+=+-12+
+x+=+-4%2F3+
check:
+log%282%2C%28x-2%29%2F%28x%2B1%29%29+
+log%282%2C%28-4%2F3+-+2%29%2F%28-4%2F3+%2B+1%29%29+
+log%282%2C%28-4%2F3+-+6%2F3%29%2F%28-4%2F3+%2B+3%2F3%29%29+
+log%282%2C%28-10%2F3%29%2F%28-1%2F3%29%29+
+log%282%2C10%29+
OK