Simplifying Expressions. CxC Maths question?

(b/b-5) - (2/b+3) They ask to simplify this equation.

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  • 1 decade ago
    Favorite Answer

    Your answerer should be easier on you since they also have the answer wrong. You can't just multiply the expression by anything you want. You have to multiply by an equivalent of one. Everything they showed you was right, but they left out the new denominator. You'd multiply the first term by (b+3)/(b+3) and the second term by (b-5)/(b-5). The final answer is actually (b^2+b+10)/((b-5)(b+3)) or (b^2+b+10)/(b^2-2b-15).

    Here's the proof. Choose any value for b you want. The value of the expression has to be the same in the original and our simplified answer. Let's make b=0. That makes the original equation 0/(0-5)-2/(0+3) or 0-2/3 or -2/3. His answer gives us 0+0+10 or 10. My answer gives us (0+0+10)/(0-0-15) or 10/-15 or -2/3 which is the same as the original expression.

  • 1 decade ago

    wow seriously?

    multiply by the common denominator which is [(b-5)(b+3)]

    then simplify

    so you get:

    b(b+3) - 2b+10= b^2 +b +10.

    so the answer is

    b^2+b+10.

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