Q. Fully simplify the expression below and write your answer as a single fraction.x4+5x33x5−75x3⋅x2−2x−15x2+10x+21Answer:
Identify and Factor Expression: Identify the expression to be simplified and factor each part where possible.The expression is (3x5−75x3)/(x4+5x3)⋅(x2+10x+21)/(x2−2x−15).Factor out common terms in the numerator and denominator.
Factor Numerator: Factor the numerator 3x5−75x3 by taking out the common factor of 3x3. 3x5−75x3=3x3(x2−25). Notice that x2−25 is a difference of squares and can be factored further.
Factor Denominator: Factor x2−25 into (x+5)(x−5).So, 3x5−75x3 becomes 3x3(x+5)(x−5).
Factor x2−25: Factor the denominator x4+5x3 by taking out the common factor of x3. x4+5x3=x3(x+5).
Factor x2+10x+21: Factor the numerator x2+10x+21 by finding two numbers that multiply to 21 and add to 10. These numbers are 3 and 7, so x2+10x+21factors into (x+3)(x+7).
Factor x2−2x−15: Factor the denominator x2−2x−15 by finding two numbers that multiply to −15 and add to −2. These numbers are −5 and 3, so x2−2x−15 factors into (x−5)(x+3).
Rewrite with Factored Parts: Now rewrite the original expression with all the factored parts: (3x3(x+5)(x−5))/(x3(x+5))×((x+3)(x+7))/((x−5)(x+3)).
Cancel Common Factors: Cancel out the common factors in the numerator and denominator.The (x+5) and x3 terms cancel out, as well as one (x+3) term.The simplified expression is now 13(x−5)×x−5x+7.
Cancel (x−5) Terms: Cancel out the common (x−5) terms in the numerator and denominator.The simplified expression is now 3×(x+7).
Final Simplified Expression: Since there are no more common factors, the expression is fully simplified. The final simplified expression is 3x+21.
More problems from Operations with rational exponents