1) Log(2)8^x= - 3 2) 5e^0.2x=7 The 2 in parenthesis is the base. What's the value of x?

1 Answer
Oct 10, 2015

I found:
x_1=-1
x_2=1.6824

Explanation:

1) you can write (definition of log):
log_2(8^x)=-3
8^x=2^-3
8^x=1/2^3=1/8
8^x=8^-1
so taking the log_8 on both sides;
x=-1

2)5e^(0.2x)=7
e^(0.2x)=7/5 taking the ln on both sides:
0.2x=ln(7/5)
x=1.6824