Question

Multiply and express your answer in standard form (-2+7i)(3+4i)

Answer 1

Answer:

-34 + 13i

Step-by-step explanation:

to solve (-2 + 7i)(3+4i), we can use FOIL which is:

First

Outside

Inside

Last

lets start off with F, we multiply the first 2 terms of each expression

(-2 + 7i)(3+4i)

this gives us -6

next is O, we multiply the 2 outside times of the expression:

(-2 + 7i)(3+4i)

this gives us -8i

I is the next step, we multiply the 2 terms on the inside:

(-2 + 7i)(3+4i)

this gives us 21i

the last step is the letter L in which we multiply the last terms of each expression:

(-2 + 7i)(3+4i)

this gives us -28, and the reason for that is because if we multiply 7i × 4i gives us 28i². i² is equal to -1, so we multiply 28 by -1 which gives us -28

so this gives us the new expression:

-6 -8i + 21i - 28

we now combine like terms which gives us the expression

-34 + 13i

this cannot be simplified any further, so this is our answer in standard form