Find the Ln (multiple)

Question

1 Solve: ln x + 2 ln 3 = 4. Just type the number, rounding to 4 decimal places, if necessary.

2 Solve: ln (2x + 5) = 3. Just type the number, rounding to 4 decimal places, if necessary.

Answer 1

1)

ln x + 2ln3 = 4

ln x + ln3^2 = 4

ln 9x = 4

9x = e^4 (raise each side as power of e)

x = e^4/9 = 6.0665

2)

ln (2x+5) = 3

2x + 5 = e^3 (raise each side as power of e)

2x = e^3 - 5

x = (e^3 - 5)/2 = 7.5428