Using symbols for solutions to equations

• {4}

• {6.557, -6.557}

• {4, -4}

• {2, -2}

Is this possible?

x²= -4

• No, because when you square a number (multiply a number by itself) it'll always be positive. 2 x 2 = 4, -2 x -2 = 4

• Yes, because a negative times a negative is negative -2 x -2 = -4

If x²=81 then x = _______.

• 9

• 18

• 27

• 36

• 4 and -4

• 2 and -2

• 1 and -1

• 5 and -5

2x²=100

• x = √25
• x = ±5√2
• x = √100
• x = ±√5

 $Solve\ 5x^2=245$ 

•  $x=7$  

•  $x=\pm15.5$  

•  $x=\pm7$  

•  $x=\pm49$  

Solve $x^2\ =\ 100$  

• x = 10

• x =  $\pm$  50

• x = 50

• x =  $\pm\$  10

Solve for x

x² = -4

• x = 2i

  x = -2i

Solve 7 $x^2$  =35

• x=5

• x=7

• x= $\pm\sqrt{7}$  

• x= $\pm\sqrt{5}$  

Given the equation 169x² = 36

What are the solutions

• x = 13

• x = 6

• $x\ =\ \frac{6}{13}$ and $x\ =\ -\frac{6}{13}$