Help Me, please
Solve the logarithmic equation, rounding decimal answers to the thousandths place
log (2x)+log(x-5)=2
x=
log (2x) + log (x -5) = 2
We can use this rule to simplify things, Manuel
log a + log b = log (a * b)....so ....we can write the left sides as
log[ (2x * (x -5) ] = 2
log [ 2x^2 - 10x] = 2 in exponential form we have
10^2 = 2x^2 - 10x
100 = 2x^2 - 10x rearrange as
2x^2 - 10x - 100 = 0 divide through by 2
x^2 - 5x -50 = 0 factor as
(x - 10)(x + 5) = 0
Setting each factor to 0 and solve for x and we have that
x = 10 or x = -5
We must reject x = -5 because it would mean that we would be taking logs of negative numbers in the original equation
So.....x = 10