Question

Explain the process of solving the following equation: 4^x - 2 = 20

Answer 1

Hi,


`4^x-2=20\\ \Rightarrow\ 4^x=22\\ \Rightarrow\ x*ln(4)=ln(22)\\ \Rightarrow\ x= (ln(22))/(ln(4))\\\\ \Rightarrow\ \boxed{ x=2,2297158...\approx{2.23}}`
ln means natural log (neper's log)

Answer 2

this is an exponential equation: 4^x - 2 = 20. First thing: combine the -2 and the 20: 4^x = 22.

Next, take the logarithm (natural or common log) of both sides. We get:

log 22
x log 4 = log 22. Then x = ----------- (answer). You could, of course, evaluate
log 4 this on a suitable calculator.