MHB Are My Algebra Answers Correct? Quick Review Needed!

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The user requested a review of their algebra answers, which included calculations for various equations. Responses confirmed that the first, third, and fourth answers were correct, although the fourth answer needed slight adjustment to t = -0.127 when rounded. The user made an error with a minus sign in the third answer, leading to an incorrect calculation for t. The correct formula for t was provided, clarifying the mistake. Overall, the discussion focused on verifying algebraic solutions and correcting minor errors.
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I have attempted the questions in the attached sheet could someone check if the answers are correct.

View attachment 1985

1. + = 1.28
- = -0.69

2. Transposed to

t = ln (P/Po) -5 / 1.2

t= -3.18

3. x = 0
x = 2.5

4. t= -0.125
s= 10.7

Thanks
 

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John Robbo said:
I have attempted the questions in the attached sheet could someone check if the answers are correct.

View attachment 1985

1. + = 1.28
- = -0.69

2. Transposed to

t = ln (P/Po) -5 / 1.2

t= -3.18

3. x = 0
x = 2.5

4. t= -0.125
s= 10.7

Thanks

Hi John Robbo, :)

Welcome to MHB! :)

The first and third and fourth answers are correct. For the fourth answer I get \(t=-0.127\) when rounded to three decimal places.

In the third answer you have messed up with a minus sign. :)

\[p=p_0 e^{5-1.2t}\]

\[\Rightarrow \ln\left(\frac{p}{p_0}\right)=5-1.2t\]

\[\Rightarrow t=\frac{1}{1.2}\left(5-\ln\left(\frac{p}{p_0}\right)\right)\]

which gives you, $t=3.18$.
 
sudharaka thanks for your help understand where I went wrong
 
John Robbo said:
sudharaka thanks for your help understand where I went wrong

You are welcome. :)
 
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