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Algebra Ch 15 Lesson 3 Number 5

Question:

I am in Algebra 1, Ch. 15, Lesson 3, # 5b. I have tried doing this in as many ways as I can think of and still have gotten the wrong answers. Mabey I am just missing something.

Answer:

Have you looked at the solutions manual? When you are confused, that needs to be the first place you check. It usually shows how a problem is worked and while you  may have some questions about some of their steps, it usually can answer the “How do they get the answer?” question you’re asking.

 

To walk you through what is in the solutions manual here is what they do:

 

They start by getting a common denominator for those two fractions. They get the common denominator by multiplying the denominators.

 

They multiply both sides by x(x+2) (The common denominator)

 

Then they perform the distributive property and simplify.

 

Lastly, they perform some algebra (combining like terms and moving things around) until they get a quadratic equation. Then they use the quadratic formula (in your book on [pg. 719) to solve for x.

 

Then they use their calculator to get a decimal they can round to the appropriate place.

 

Take a look at the solutions manual along with these step by step instructions and you should get a good idea of what is going on in the problem. However, if after you’ve tried the problem again you still have questions I can add more clarification if you need.

 

I hope this helps!

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Algebra Test 3

Algebra Test 3 #13

 

Question: Test 3, Number 13: Answer book says number gets smaller by 7. Yes, the number gets 7 digits smaller but the question is asking about what happens to the exponent – doesn’t the exponent get larger by 7? That’s what we were thinking but we are no experts so here we are asking! Thanks!

Answer: When you are moving to the left with the decimal, the exponent is getting smaller. Let’s work through an example to show you what I mean:

If we start with the number 6,000

That’s 6 x 10^3 in scientific notation.

If I take the decimal in 6,000 and move it 7 places to the left I end up with

.0006000 = .0006 = 6 x 10^ -4

Notice that the exponent goes from 3, to –4, which is a difference of 7 digits in the negative direction. So we say the exponent gets 7 digits smaller.

I hope this helps!