Question

solve

Answer 1

\[5^{3x}=0.04\]

Answer 2

Have you learnt natural logarithm before?

Answer 3

not to good at it

Answer 4

If you ln both sides,
\[\ln(5^{2x})=\ln(0.04)\]
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Using rule
\[\ln(a^b)=b \ln(a)\]
------------------------
\[2x \ln(5)=\ln(0.04)\]
Divide both sides by 2ln(5) and you're done

Answer 5

maan that is confusing

Answer 6

what doi do with the 2x?

Answer 7

The last part?

Answer 8

yeah

Answer 9

i reallydon t' understand In either. IS there a formula i should know

Answer 10

You want to get x alone, so
\[\color{red}{2}x \color{red}{\ln(5)}=\ln(0.04)\]
\[x=\frac{\ln(0.04)}{2\ln(5)}\]

Answer 11

The formula we used here is just \(\ln(a^b)=b \ln(a)\), you need to practice more of them

Answer 12

x=-4?

Answer 13

Nope

Answer 14

For \(x=\frac{\ln(0.04)}{2\ln(5)}\) you can just use a calculator for that

Answer 15

do i multiply 2 by ln(5)?

Answer 16

i got -4still

Answer 17

how about x=-2/3

Answer 18

the answer is not a fraction

Answer 19

\[x=\frac{ \ln 0.04 }{ \ln 25}=-1\]
\[5^{5\times(-1)}=0.04\]