Dwayne wrote a two-digit number. He multiplied it by 3, added 18, and divided by 8. His final answer was 9. What number did Duwa
yne write?
1 answer:
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Answer:
Step-by-step explanation:
Solve this by using natural logs. Taking the natural log of both sides:
To undo the multiplication, we use addition:
The rule says we can now bring the exponent down in front of the ln:
Now we will subtract ln(7) from both sides:
(8x - 8)ln(16) = ln(3) - ln(7)
Now we will divide both sides by ln(16):
then add 8 to both sides:
which simplifies to
8x = 7.694401895 so
x = .9618002368 or, rounded,
x = .96
(Rest assured I did the math and checked the answer and it checked out perfectly!) I recommend you learn the laws of natural and common logs cuz they're kinda important!! :)