Question

(4-3i)(1+2i)
I have so many of these

Answer 1

-2 + 5i

Explanation:

Remember these rules:

real times real = real (e. g., 4(1) = 4)

real times imaginary: imaginary (e. g., 4(2i) = 8i)

imaginary times real imaginary

imaginary times imaginary: real with a negative sign (e. g., (-3i)(2i) = +6

Once again: work out (-3i)(2i). We get (i^2)(-6) = +6

In summary: your (4-3i)(1+2i) becomes 4 + 8i - 3i - (i^2)(-6), or

4 + 5i - 6, or -2 + 5i

Answer 2

-6i^2+5i+4

Explanation:

Rearrange Terms

(-3i+4)(1+2i)

(-3i+4)(2i+1)

Distribute

-3(2i+1)+4(2i+1)

-6i^2-3i+4(2i+1)

-6i^2-3i+4(2i+1)

-6i^2-3i+8i+4

Combine Liker Terms

-6i^2+5i+4

Solution

-6i^2+5i+4