Question

Simplify the given expression:

(1 + 2i) • (5 − 3i)

Answer 1

Use foil.

Answer 2

?

Answer 3

1 * 5 = a
2i * 5 = b
1 * -3i = c
2i * -3i = d

a + b - c - d
Simplify.

Answer 4

i still dont understand math is a little hard for me to get

Answer 5

Jcpd910. Mind explaining?

Answer 6

1 * 5 = a =1
2i * 5 = b =10i

So you plug in the values into the equation

a = 1
b = 10i

1 + 10i - c - d

Answer 7

i get it thanks !

Answer 8

No problem. :D

Answer 9

it doesnt give me any of my choices .2 − 15i

3 + 2i

5 − 6i

11 + 7i

Answer 10

unless im still doing it wrong

Answer 11

Show me your work please.

Answer 12

1 * 5 = a =1
2i * 5 = b =10i
Okayy Here Why Did You Say 5* 1 = 1?

Answer 13

Oh, I'm sorry I meant 5. lol

Answer 14

thats okay so this is what i got 1*5=5
2i*5=10i
1 *-3i=-3i
2 * -3i=-6i

Answer 15

Okay, I'm getting confused. Are you using i as an imaginary number or as a variable?

Answer 16

imaginary number

Answer 17

Okay, well let's see now.

(1 + 2i) • (5 − 3i)
5 + 10i - 3i - 6i^2

Do you know what i^2 =?

Answer 18

-1

Answer 19

Yes, so
5 + 10i - 3i -(6(-1)
5 + 10 - 3i + 6
11 + 7i

Answer 20

Sorry, I thought i was a variable.

Answer 21

So now you got your answer.

Answer 22

thank you

Answer 23

No problem. :)