Math Is Fun Forum

You put 10ln(8)-1-5ln(4)-1, but it should be 10ln(8)-10-5ln(4)+5. Because ax(ln(ex)-b)-cx(ln(fx)-d)= axln(ex)-abx-cxln(fx)+cdx.
That was some bad distribution of negative and positive signs and also numbers.
That can be simplify to 5(ln(64)-ln(4)-1).
Which gives you 5(ln(16)-1), because ln(a)-ln(b)= ln(a/b)
That is equal to ln(1,048,576)-5, because aln(b)=ln(b^(a))
My instructors will preferred 5(ln(16)-1) as an answer.