Number of Solutions
Solve by Graphing
Factoryng
Solving by Factoring
Mystery...

Or is it?
101

The number of solutions for the equation 

x^2=81

2 Solutions

x=9

x=-9

101

The number of solutions to the equation

x^2+5x+9=0

No Solution.


The graph doesn't have an x-intercept.

101

Rewrite the expression in factored form. If it cannot be done, write "cannot be done".

x^2-400

(x+20)(x-20)

101

Solve by factoring.

4x^2=16x

x=0 and x=4

4x^2-16x=0

4x(x-4)

101

Solfe the equation.


(x-4)(2x+6)=0

x=4 and x=-3

200

The number of solutions for the equation

9x^2=0


1 Solution

x=0

200

The number of solutions to the equation

x^2-5x-36=0

3 Solutions.

The graph has x-intercepts at -4 and 9.

200

Rewrite the expression in factored form. If it cannot be done, write "cannot be done".


x^2+16


Cannot be done.

200

Solve by factoring.

x^2-x-6=0



x=3 and x=-2


(x-3)(x+2)=0

200

Kiran is solving the equation given below. His first step was to divide both sides by 4x. He says the only solution is x=0.5. Explain to Kiran why dividing by 4x is not a good first step and find both solutions to the equation.

8x^2=4x

Dividing by 4x is not valid when x=0, because it would mean dividing by 0.


Instead, Kiran should subtract 4x from both sides. Then he can factor the equation as shown below and get solutions of x=0 and x=0.5.


8x^2-4x=0

4x(2x-1)=0

300

The number of solutions to the equation

x^2=-25

No Solutions.

A number squared cannot equal a negative number.

300

The number of solutions to the equation

x^2-4x+4=0

1 Solution.

The graph has one x-intercept at 2.

300

Rewrite the expression in factored form. If it cannot be done, write "cannot be done".


25x^2-9/16

(5x+3/4)(5x-3/4)

300

Solve by factoring.

x^2+9x+20=0



x=-4 and x=-5


(x+4)(x+5)=0

300

Choose the expressions that are equivalent to 

x^2+4x+3

A.  (x+2)^2-1

B.  (x+2)^2+1

C.  (x-1)(x-3)

D.  (x+1)(x+3)

E.  (x-1)(x+4)

A and D

400

The number of solutions to the equation is 2.

x^2-5=31

I already told you the answer why are you here?

x=6

x=-6

400

Here is a graph. Lin says that the equation

-x^2-4=0

has 1 solution because the y-intercept is at -4. Determine if Lin is correct.

Lin is incorrect. This equation has no solutions because it doesn't have an x-intercept. Lin accidentally looked at the y-intercept instead of the x-intercept.

400

Rewrite the expression in factored form. If it cannot be done, write "cannot be done".


x^2+2x-24



(x-4)(x+6)

400

Solve by factoring.

x^2-1600=0



x=40 or x=-40


(x-40)(x+40)=0

400

The two expressions below are equivalent. Find the values of a and b that make the expressions equivalent.

5x^2+bx-12

(5x+a)(x-4)

a=3 and b=-17

500

The number of solutions to the equation is 2.

(x+4)(x-4)=0

I already said the answer... Why are you here?

x=-4

x=4

500

How can the graph tell us how many solutions there are?

The number of x-intercepts reveals the number of solutions.

500

Rewrite the expression in factored form. If it cannot be done, write "cannot be done".


t^2-5t+6

You're mistaken...

500

Solve by factoring.


x^2-2x-24=0

x=-4 and x=6


(x+4)(x-6)=0

500

A fenced-in community garden currently has a square plot of land with a side length of x. They decide to change the shape of the garden to a rectangle while still using the same amount of fencing materials. The equation below represents the relationship of the new side lengths with the garden's area. Find the original side length of the garden.

(x+5)(x-5)=299

x=18 (a negative value for x wouldn't make sense)

x^2-25=299

x^2=324

x=18 or x=-18