Algebra

Cranberry557

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Jun 8, 2009
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Hi, i am a 8th grade student and am in Algebra I. I need help simplifying the expression: 20x^3y/ 4xy^2 * -6yx/-x
( the * is a multiplication sign) The first thing that i tried to so is simpilify 20 and 4 which is 5 and then subtract x^3 and x^2 to get just "x". Then i subtracted y and y^2 and got -y. my final answer i got was 5x^2/y. can you tell me if this is correct please?
 
Cranberry557 said:
Hi, i am a 8th grade student and am in Algebra I. I need help simplifying the expression: 20x^3y/ 4xy^2 * -6yx/-x
( the * is a multiplication sign) The first thing that i tried to so is simpilify 20 and 4 which is 5 and then subtract x^3 and x^2 to get just "x". Then i subtracted y and y^2 and got -y. my final answer i got was 5x^2/y. can you tell me if this is correct please?

First - let us re-write your problem

Simplify:

\(\displaystyle \frac{20x^3y}{4xy^2} \cdot \frac{-6yx}{-x}\)

Is this the statement of your problem?
 
20x^3 y / (4x y^2)

Do you agree that simplifying that one leaves 5x^2 / y ?
 
20x^3 y / (4x y^2) * -6yx / -x NOTE: the set of brackets I've inserted is a MUST; agree?

OK; so we agree that 20x^3 y / (4x y^2) = 5x^2 / y

Similarly, -6yx / -x = 6y ; agree?

So we now have 5x^2 / y * 6y, or 30x^2 y / y ; right?

I'll let you have the fun of finishing it!

By the way, you can check yourself if your ending simplification is correct by assigning any
values to x and y, say x=5 and y=2, then substituting these in the original expression and
in the simplification: both should end up with same value...kapish?
 
Okay so then you get 5x^2/y */ 6y/1 and you cancel out the y's and you multiply 5 and 6 for get a final answer of 30x^2 ? I also have a quick question that doesn't have to do with this problem, what is a discriminate? Thanks for all your help!
 
Cranberry557 said:
Okay so then you get 5x^2/y */ 6y/1 and you cancel out the y's and you multiply 5 and 6 for get a final answer of 30x^2 ? I also have a quick question that doesn't have to do with this problem,

what is a discriminate? <<< do a google search

Thanks for all your help!
 
Subhotosh Khan said:
Cranberry557 said:
Okay so then you get 5x^2/y */ 6y/1 and you cancel out the y's and you multiply 5 and 6 for get a final answer of 30x^2 ? I also have a quick question that doesn't have to do with this problem,

what is a discriminate? <<< do a google search

Thanks for all your help!

I agree that a Google search should be helpful. But, I think you will want to search under the correct spelling, which is discriminant
 
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