SOLUTION: (3-71)(3+7i) (2-2i)(2+2i) (7-10i)(7+10i) (2+5i)(2-5i) (4+3i)(1-i) (5-7i)(1+2i) (2-5i)(2-5i)

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: (3-71)(3+7i) (2-2i)(2+2i) (7-10i)(7+10i) (2+5i)(2-5i) (4+3i)(1-i) (5-7i)(1+2i) (2-5i)(2-5i)      Log On


   



Question 447466: (3-71)(3+7i)
(2-2i)(2+2i)
(7-10i)(7+10i)
(2+5i)(2-5i)
(4+3i)(1-i)
(5-7i)(1+2i)
(2-5i)(2-5i)

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi,
These can be done as one would use the FOIL method: Note: i^2 = -1
F First terms
O Outside terms
I Inside terms
L Last terms
(3-7i)(3+7i) = 9+49 = 58 | SUM of the outside terms and the inside terms = 0
(2-2i)(2+2i) = 4 + 4 = 8 | SUM of the outside terms and the inside terms = 0
(7-10i)(7+10i) = 49 + 100 = 149 | SUM of the outside terms and the inside terms = 0
(2+5i)(2-5i) = 4+ 25 = 29 | SUM of the outside terms and the inside terms = 0
(4+3i)(1-i) = 4 - i + 3 = 7 -i
(5-7i)(1+2i) = 5 +3i + 14 = 19 + 3i
(2-5i)(2-5i) = 4 -20i - 25 = 29 - 20i
Note: -5i*-5i = 25*-1