Let's start making our expression.
Just take the number 40 and change it around.

That's a good start.
49 is equal to 7×7, or 7². 9 is equal to 3×3, or 3².
So we can also write this as

You can really do whatever you want with it as long as it's still 40, just make sure you've got an exponent there. Here's another example.
First, plug Y into the equation
16=-5x+4
Get variables on one side and numbers on the other
Subtract 4 from both sides
12=-5x
X= 12/5
Problem 1)
The base of the exponential is 12 which is also the base of the log as well. The only answer choice that has this is choice B.
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Problem 2)
log(x) + log(y) - 2log(z)
log(x) + log(y) - log(z^2)
log(x*y) - log(z^2)
log[(x*y)/(z^2)]
Answer is choice D
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Problem 3)
log[21/(x^2)]
log(21) - log(x^2)
log(21) - 2*log(x)
This matches with choice B
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Problem 4)
Ln(63) = Ln(z) + Ln(7)
Ln(63)-Ln(7) = Ln(z)
Ln(63/7) = Ln(z)
Ln(9) = Ln(z)
z = 9
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Problem 5)
Ln(5x-3) = 2
5x-3 = e^2
5x = e^2+3
x = (e^2+3)/5
This means choice A is the answer
9514 1404 393
Answer:
400 mL/h
Step-by-step explanation:
The required rate is ...
(100 mL)/(1/4 h) = 100×(4/1) mL/h = 400 mL/h