Use the quadratic formula to answer the questions below.

Quadratic Formula is x= −b ±b2−4ac√2a


The equation is 2x2+22x+60


Fill in the blanks below (yellow boxes).

(1 point)
Part A: GCF The GCF is = ____
The quadratic with the factored out the GCF is : ____
a = b= c=
Part B: Use the quadratic formula ___ ± ___^2 - 4(__) (__)
_____________________
2(__)
Part C: solve for x
x = (lesser number)
x = (greater number)

1 answer

To solve the problem using the quadratic formula, we'll work through each part step by step.

Part A: GCF

  1. Finding the GCF: The given quadratic is \( 2x^2 + 22x + 60 \). The GCF of the coefficients (2, 22, and 60) is 2.

    The GCF is = 2

  2. Factoring out the GCF: We can factor out the GCF from the quadratic expression: \[ 2(x^2 + 11x + 30) \] The quadratic with the factored out the GCF is: \( 2(x^2 + 11x + 30) \)

  3. Values of a, b, and c: After factoring out the GCF, the coefficients for the quadratic \( x^2 + 11x + 30 \) are:

    • \( a = 1 \)
    • \( b = 11 \)
    • \( c = 30 \)

Part B: Use the quadratic formula

We will now calculate using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]

Plugging in the values from Part A:

  • \( a = 1 \)
  • \( b = 11 \)
  • \( c = 30 \)

The formula becomes: \[ x = \frac{-11 \pm \sqrt{11^2 - 4(1)(30)}}{2(1)} \]

We compute: \[ 11^2 = 121 \] \[ 4(1)(30) = 120 \] So, \[ x = \frac{-11 \pm \sqrt{121 - 120}}{2} \] Thus, \[ x = \frac{-11 \pm \sqrt{1}}{2} \]

Part C: Solve for x

Now, we can simplify the expression: \[ \sqrt{1} = 1 \]

So our expression for \( x \) is: \[ x = \frac{-11 \pm 1}{2} \]

Calculating the two solutions:

  1. For the lesser number: \[ x = \frac{-11 - 1}{2} = \frac{-12}{2} = -6 \]

  2. For the greater number: \[ x = \frac{-11 + 1}{2} = \frac{-10}{2} = -5 \]

Summary of Answers

Part A:

  • GCF is = 2
  • The quadratic with the factored out the GCF is: \( 2(x^2 + 11x + 30) \)
  • \( a = 1 \)
  • \( b = 11 \)
  • \( c = 30 \)

Part B:

  • Use the quadratic formula: \[ -11 \pm 1^2 - 4(1)(30) \] \[ \frac{}{} (2(1)) \]

Part C:

  • Solve for x:
    • \( x = -6 \) (lesser number)
    • \( x = -5 \) (greater number)