How do you solve e12−5x−7=123?

1 Answer
Sudip Sinha
Jul 30, 2015

x=15(12−ln(130))

Explanation:

e12−5x−7=123
⇒e12−5x=123+7=130 (Add 7 to both sides)
⇒12−5x=ln(130) (Take natural logarithm on both sides)
⇒−5x=−12+ln(130) (Add -12 to both sides)
⇒5x=12−ln(130) (Multiply by -1)
⇒x=15(12−ln(130)) (Divide by 5 on both sides)

If you need, you may use a calculator to get log(130)=4.8675. Put this value to get x=1.4265.

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