I'm having trouble solving these two problems:
1.)
2.)
Your assistance is much appreciated.
Ignore the solution to the first question, there's a mistake in it.
log_c a + log_c b = log_c a.b
So,
log_2(x+7) + log_2(x) = 3
log_2{x^2 + 7} = 3
x^2 + 7 = 2^3 = 8
x^2 = 1
x={-1,1}
Don't forget to check the results because x+7 > 0 and x>0.
Ah, x = -1 doesn't satisfy x>0. So we remove it from the solution set.
x=1
----------------------------------------------
Let
Multiply both sides by a,
Put these a values back in ,
(Not real!)
(We exclude this because it's impossible to have such real x)