Q:

Donte simplified the expression below. mc024-1.jpg What mistake did Donte make? He did not apply the distributive property correctly for 4(1 + 3i). He did not distribute the subtraction sign correctly for 8 – 5i. He added the real number and coefficient of i in 4(1 + 3i). He added the two complex numbers instead of subtracted.

Accepted Solution

A:
The expression simplified by Donte is:

4(1 + 3i) – (8 – 5i) = –4 + 8i

And the set of options are:

What mistake did Donte make?
A.He did not apply the distributive property correctly for 4(1 + 3i).
B.He did not distribute the subtraction sign correctly for 8 – 5i.
C.He added the real number and coefficient of i in 4(1 + 3i).
D.He added the two complex numbers instead of subtracted.

Answer: option A: he did not apply the distributive property correctly for 4(1 + 3i)

Explanation:

The correct application leads to: 4*1 + 4*3i = 4 + 12i

If you, incorrectly, make 4*1 + 3i, then you get 4 + 3i, and when you subtract (8 - 5i) you get:

4 + 3i - (8 - 5i) = 4 + 3i - 8 + 5i = - 4 + 8i which is what Donte obtained..

Therefore, he applied the distrituvie property incorrectly for 4(1 + 3i)