Pre-cal.. please help!!!

[daisyblue]

1. 12+5i
-----------
-1 +2i

2. Find [z] if z= -6+7i


3. if z1= 7+5i and z2= 3+2i, find[z1-3z2]

4. 3p2 + 2p =4

5. 4w2 -8w+5=0
I have an idea on how to do them, but I don't end up with the right answer.

 

[Matt]

What does [z] mean?

 

[tkhunny]

1. 12+5i
-----------
-1 +2i

2. Find [z] if z= -6+7i

1. Are we to simplify? Rationalize the Denominator? Please provide complete problem statements and some indication of your efforts to date.

Multiply numerator and denominator by the complex conjugate of the Denominator, -1 - 2i

2. Is [z] the Magnitude of z? The vertical bars would be more standard notation, |z|. Please provide complete problem statements and some indication of your efforts to date.

Draw a right triangle with legs of length 6 and 7. Use the Pythagorean Theorem to calculate the length of the Hypotenuse.