Identify Coefficients: Identify the coefficients of the quadratic expression.The quadratic expression is 3x2−2x−5. Here, the coefficient of x2(a) is 3, the coefficient of x(b) is −2, and the constant term (c) is −5.
Determine Factoring Feasibility: Determine if the quadratic expression can be factored using simple factoring techniques.Since the coefficient of x2 is not 1, we need to find two numbers that multiply to ac (3×−5=−15) and add up to b (−2). We are looking for two numbers that multiply to −15 and add up to −2.
Find Suitable Numbers: Find two numbers that meet the criteria.After checking possible pairs of factors of −15, we find that there are no two integers that multiply to −15 and add up to −2. Therefore, we cannot factor this quadratic expression using simple factoring techniques.
Use Quadratic Formula: Use the quadratic formula to check if the expression can be factored over the real numbers.The quadratic formula is x=2a−b±b2−4ac. For our expression, a=3, b=−2, and c=−5. Let's calculate the discriminant b2−4ac to see if the roots are real numbers.Discriminant = (−2)2−4(3)(−5)=4+60=64.Since the discriminant is positive, we have two distinct real roots.
Calculate Roots: Calculate the roots using the quadratic formula.x=2×3−(−2)±64x=62±8We have two roots: x=6(2+8) and x=6(2−8)x=610 and x=6−6x=35 and x=−1
Write Factored Form: Write the factored form using the roots.The factored form of the quadratic expression is (3x−5)(x+1).