Q. Perform the following operation and express in simplest form.x−9x2+9x÷x2−7x−18x2−81Answer:
Identify and Rewrite Division: Identify the given expression and rewrite the division as multiplication by the reciprocal.The expression is (x2+9x)/(x−9)÷(x2−81)/(x2−7x−18), which can be rewritten as (x2+9x)/(x−9)×(x2−7x−18)/(x2−81).
Factor Numerator and Denominator: Factor the numerator and denominator of both fractions where possible.The numerator x2+9x can be factored as x(x+9).The denominator x2−81 can be factored as (x+9)(x−9) because it is a difference of squares.The denominator x2−7x−18 can be factored as (x−9)(x+2) because it is a quadratic expression.
Rewrite with Factored Terms: Rewrite the expression with the factored terms.The expression becomes (x(x+9))/(x−9)×((x−9)(x+2))/(x+9)(x−9).
Cancel Common Factors: Cancel out common factors from the numerator and denominator.The factors (x+9) and (x−9) cancel out from the numerator and denominator.The expression simplifies to x×(x+2).
Multiply Remaining Factors: Multiply the remaining factors.Multiplying x by (x+2) gives x2+2x.
Check for Further Simplification: Check for any further simplification. The expression x2+2x cannot be factored further, so this is the simplest form.
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