How do you solve #e^(12-5x) -7 = 123#?

1 Answer
Sudip Sinha
Jul 30, 2015

# x = 1/5 (12 - ln(130)) #

Explanation:

# e^(12−5x)−7 = 123 #
# => e^(12−5x) = 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 = 1/5 (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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