Question

Multiply.
1.) 7i (3-7i)
2.) (4+3i) (3-3i)

Answer 1

1.) 7i (3-7i)=7i *3 - 7i * 7i = 21i - 49*i^2=49+21i ;
2.) (4+3i) (3-3i) = 4*3+4*(-3i)+3i*3+3i*(-3i)=12-12i+9i-9*i^2=12-3i+9=21-3i

Answer 2

is that by rationalizing ?

Answer 3

ah, rationalizing is a process to turn the denominator which is probably not a rational to a national.

Answer 4

rational,...

Answer 5

rational,...

Answer 6

so if i wanted to rationalize 10/1+3i ?

Answer 7

you mean 10/(1+3i)？？ you'd better use the brackets to avoid misunderstanding

Answer 8

and same process if i want to add or subtract ?

Answer 9

yes 10/(1+3i), sorry i've never done math online

Answer 10

you understand the two methods: traditional one, and rationalization??

Answer 11

rationalization is longer ?