U9L3 Complex Solutions

Find the roots of the following quadratics:

 $2x^2+6x=11$  

•  $\left\{\frac{11}{2},8\right\}$  

•  $\left\{-2\sqrt{31},\ -\sqrt{31}\right\}$  

•  $\left\{\frac{-3+\sqrt{31}}{2},\ \frac{-3-\sqrt{31}}{2}\right\}$  

• No Solutions

Solve for x: 

• x = {-4, -1}
• x = {-1, -4}
• x = {2+i, 2-i}
• x = {-2+i, -2-i}

Tags

CCSS.HSA-REI.B.4B

CCSS.HSN.CN.C.7

Express  $\sqrt{-225}$  in terms of  $i$  

•  $15i$  

•  $-15i$  

•  $i\sqrt{15}$  

•  $-i\sqrt{15}$  

Solve the equation $x^2+8x+20=0$  

•  $-4\pm2i$  

•  $2i\pm4$  

•  $-2\pm4i$  

•  $3\pm2i$  

 $f\left(x\right)=x^2-2x+17$  

•  $1\pm4i$  

•  $4\pm i$  

•  $-1\pm4i$  

•  $-4\pm i$  

Find the roots:
 $x^{2\ }+6x+13$ 

• x = {-3 + 2i, -3 - 2i}

• x = {7, 6}

• x = 2 ± i√3

• No solution

Solve for x:
 $x^2-5x+8=0$ 

•  $x=\left\{\frac{-5\pm i\sqrt{7}}{2}\right\}$ 

•  $x=\left\{\frac{5\pm i\sqrt{7}}{2}\right\}$  

•  $x=\left\{\frac{8\pm i\sqrt{7}}{2}\right\}$  

•  $x=\left\{\frac{5\pm\sqrt{57}}{2}\right\}$  

Solve:
 $x^2+6x+27=0$  

•  $3\pm\sqrt{18}$  

•  $3\pm i\sqrt{18}$  

•  $-3\pm i\sqrt{18}$  

•  $-3\pm\sqrt{18}$  

Solve the equation $3x^2+96=0$  

•  $\pm4\sqrt{2}$  

•  $\pm4i\sqrt{2}$  

•  $2i\sqrt{4}$  

•  $\pm2\sqrt{4}$  

Solve the following quadratic.  $x^2-11x-31=-12$  

•  $\frac{11\pm\sqrt{51}}{2}$  

•  $\frac{11\pm\sqrt{197}}{2}$  

• 11 $\frac{11\pm\sqrt{293}}{2}$  

•  $\frac{11\pm3\sqrt{5}}{2}$ 

Answer explanation

Make sure you:
ADD 12 to both sides to get equation = 0
 put -11 in (   ) for when you square it, should = 121. 
Your "C" value is - 19

Tags

CCSS.HSA.REI.B.4