Step-5

Title: Quadratic-Equations and Factors

Grade: 1300-a Lesson: S2-L1

Explanation: Hello Students, time to practice and review the steps for the problem.

Lesson Steps

Step Type Explanation Answer

1

Problem

Solve the quadratic equation \$2x^2 + x - 4 = 0\$ by completing the square.

2

Step

Rearrange the equation by shifting the constant term
(- 4) to the opposite side

\$2x^2 + x = 4\$

3

Clue

Divide the entire equation by the coefficient of \$x^2\$ to ensure the leading coefficient becomes 1

\$x^2+(1/2)x = 2\$

4

Hint

Take half of the coefficient of the x term, square it, and add it to both sides of the equation:

\$x^2 + 2 (1/4)x + 1/16 = 2 + 1/16\$

5

Step

Square the left side of the equation and express it as a perfect square by factoring

\$(x + 1/4)^2 = 33/16\$

6

Step

Solve for x by finding the square root of each side

\$x + 1/4 = ± \sqrt(33)/4\$

⇒\$x = - 1/4 ± \sqrt(33)/4\$

7

Step

Hence, completing the square for the quadratic equation \$2x^2 + x - 4 = 0\$ yields solutions: \$x = (- 1 + \sqrt(33))/4\$ and \$x = (- 1 - \sqrt(33))/4\$.

8

Choice.A

The solutions given for the quadratic equation are not applicable

\$x = (- 1 + \sqrt(33))/2\$ and \$x = (- 1 - \sqrt(33))/2\$

9

Choice.B

The solutions given for the quadratic equation are not applicable

\$x = ( 1 + \sqrt(33))/2\$ and \$x = ( 1 - \sqrt(33))/2\$

10

Choice.C

The solutions given for the quadratic equation are not applicable

\$x = ( 1 + \sqrt(33))/4\$ and \$x = ( 1 - \sqrt(33))/4\$

11

Choice.D

The pair of solutions align with the provided quadratic equation

\$x = (- 1 + \sqrt(33))/4\$ and \$x = (- 1 - \sqrt(33))/4\$

12

Answer

Option

D

13

Sumup

Can you briefly tell me what you’ve learned and understood in today’s lesson?


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