Q. 30−6x−x2x2+6x−30Which expression is equivalent to the given expression for all x2+6x−30=0 ?Choose 1 answer:(A) −1(B) 1(C) 0(D) (6−x)(5+x)(x+6)(x−5)
Factor Numerator: Factor the numerator x2+6x−30. To factor the quadratic expression, we look for two numbers that multiply to −30 and add to 6. These numbers are 10 and −5. So, x2+6x−30 can be factored as (x+10)(x−5).
Factor Denominator: Factor the denominator 30−6x−x2. Notice that this is a quadratic expression that can be rewritten in standard form as −x2−6x+30. To factor this expression, we look for two numbers that multiply to 30 and add to −6. These numbers are −10 and 5. However, since the quadratic has a negative leading coefficient, we can factor out a negative sign to make it easier to see the factors: −(x2+6x−30). Now, we can factor the expression inside the parentheses as −(x+10)(x−5).
Write Expression: Write the original expression with the factored numerator and denominator.The original expression (x2+6x−30)/(30−6x−x2) can now be written as ((x+10)(x−5))/(−(x+10)(x−5)).
Simplify Expression: Simplify the expression by canceling out common factors.We can cancel out the common factors (x+10)(x−5) in the numerator and the denominator, but we must also remember the negative sign in the denominator.After canceling, we are left with −1, since the negative sign does not cancel out.