Solving Quadratic Equations with Factoring

To solve a quadratic equation by factoring, the equation MUST be in 
standard form:  ax²+bx+c=0.

• True
• False

What would be the first step to solve the equation x²-x-72 = 0 by factoring?

• Set -x = 0 and -72 = 0
• Put in standard form.
• Factor by finding two numbers whose product is -72 and sum is -1.
• Factor out an x.

Solve by factoring: x² - 9x + 20 = 0

• x = -4 and x = -5
• x = 20 and x = -9
• x = 4 and x = 5
• x = -4 and x = 5

Tags

CCSS.HSA-REI.B.4B

What would be the first step to solve the equation x²-20x = -51 by factoring?

• Factor by finding two numbers whose product is -51 and sum is -20.
• Put in standard form by adding 51 to both sides.
• Put in standard form by subtracting 51 from both sides.
• Set x² = -51 and -20x = -51, and solve both equations for x.

Solve by Factoring:
y² + 2y = 15

• y = 3 and y = -5
• y = -3 and y = -5
• y = -3 and y = 5
• y = 3 and y = 5

Tags

CCSS.HSA-REI.B.4B

What would be the first step to solve the equation 5x² - 20x + 25 = 0 by factoring?

• Put in standard form.

• Factor by finding two number whose product is 25 and sum is -20.

• Subtract 25 from both sides.

• Factor out the GCF; which is 5.

Solve and find your zeros:
2x²+10x-12 =0

• x = -6, 1
• x = -12, 1
• z= 6, -1
• z= 2, 3

Tags

CCSS.HSA-REI.B.4B

Which equation below would be the result of completing the first step for solving  x² + 2 = -3x by factoring?

• x² + 5x = 0
• x² + 3x + 2 = 0
• - 2x² +2 = 0
• x² - 3x + 2 = 0

What is the first step in solving 
(x + 2)(x - 3) = 0      ?

• Plug in zero for x.
• Combine 2 and -3.
• Distribute the x and 2
• Set each binomial factor equal to zero and solve for x.

Solve for the values of x:

2x² +7x - 4 = 0

• { 1/2, -4 }

• { 1/2, 4 }

• { 2, -4 }

• { -1, 4 }