SOLUTION: (3+4i)(1-2i)
Algebra.Com
Question 244809: (3+4i)(1-2i)
Found 2 solutions by richwmiller, MathTherapy:
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
(3+4i)(1-2i)
remember that i=sqrt(-1)and that i^2=-1
use foil
first term 3*1=3
outer terms 3*2i=6i
inner terms 1*4i=4i
add (6+4)(i)=10i
last terms 4i*2i=8(-1)=-8
3+10i-8
10i-5
Answer by MathTherapy(10552) (Show Source): You can put this solution on YOUR website!
(3+4i)(1-2i)
Foil the binomials:
F ------- 3 * 1 = 3
O ------- - 2i * + 3 = - 6i
I ------- + 4i * 1 = + 4i
L ------- + 4i * - 2i = = - 8(-1) = + 8
Putting them together, we get: 3 - 6i + 4i + 8
Combining like terms gives us:
RELATED QUESTIONS
(1+2i)/(3-4i)+(2-i)/5i
(answered by MathLover1,Alan3354)
(7+2i)+(1-4i) (answered by jim_thompson5910)
(3-2i)+(7-4i) (answered by stanbon)
(3+2i) +... (answered by Alan3354)
2i over... (answered by Fombitz)
(3-2i)-(2+4i)
(answered by Edwin McCravy)
(2-4i)(-6+4i)
(-3+2i)(-6-8i)
(8-6i)(-4-4i)
(1-7i)squared
6(-7+6i)(-4+2i) (answered by Alan3354)
divide... (answered by jim_thompson5910)
-8-(3+2i)-(9-4i) (answered by jim_thompson5910,ewatrrr)