Algebra Problem in Textbook: Can't Figure Out the Step!

In summary, the problem involves simplifying an expression and the next step involves finding a common denominator to continue the simplification process. The confusion may have arisen due to the way the expression was written in the textbook.
  • #1
kuahji
394
2
A problem in my textbook shows
25/9(20-y)^2 = 144+(20-y)^2
Then the very next step shows
16/9(20-y)^2=144

Maybe its just me, but I can't seem to figure out the algebra behind this step in the problem, any ideas on where to start? I thought about subtracting/dividing the (20-y)^2 from the right side, but that seems to be getting me nowhere.
 
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  • #2
(20-y)^2=(9/9)(20-y)^2. You just need a common denominator.
 
  • #3
Thanks, not sure why but I didn't even thing about the 9 being in the denominator in the first term. Probably because of the way it was written.
 
  • #4
No, the main reason why students overlook this sort of thing, is that they don't consider an expression like (20-y)^2 as JUST ANOTHER NUMBER, but as something far more etheral and mysterious.
 
  • #5
If it was actually written 25/9(20-y)^2 in your book then I can see your confusion. What you give means
[tex]\frac{25}{9}(20-y)^2[/tex]
but you might confuse it with
[tex]\frac{25}{9(20-y)^2}[/tex]
I can see no good reason for not using the "clear" form in a printed textbook.
 

FAQ: Algebra Problem in Textbook: Can't Figure Out the Step!

1. How do I approach solving an algebra problem in a textbook?

The first step is to carefully read the problem and identify what is being asked for and what information is given. Then, try to simplify the problem by using known algebraic rules and properties. If you are still stuck, try working backwards from the answer or breaking the problem into smaller parts.

2. Why can't I figure out a step in the algebra problem?

There could be several reasons for this. It is possible that you are unfamiliar with a certain algebraic concept or rule that is needed to solve the problem. In this case, it would be helpful to review your notes or textbook to refresh your understanding. It is also possible that there is a mistake in the problem or your calculations. Double check your work and try approaching the problem from a different angle.

3. How do I know if I am using the correct algebraic steps?

If you are following the correct rules and properties of algebra, you should be able to arrive at the correct solution. However, it is always a good idea to check your work by plugging in the solution back into the original problem to see if it satisfies all the given conditions.

4. Is there a specific order in which I should solve the algebra problem?

Yes, there is a recommended order of operations in algebra, also known as PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction). It is important to follow this order to avoid errors and arrive at the correct solution.

5. What should I do if I am still stuck on the algebra problem?

If you have tried different approaches and are still unable to solve the problem, it may be helpful to seek assistance from a teacher, tutor, or classmate. You can also try looking for similar examples and practice problems online or in your textbook to gain a better understanding of the concept.

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