Question

Multiply 3i(8-i).
Subtract 4-(-2+3i)-(-4-i).

Answer 1

for the first one what do you think?

Answer 2

3+24i. But why?

Answer 3

because 3i*8 = 24i and 3i*(-i)=-3i^2 and i^2=-1 so 3i*(-i)=3 and therefore you have 24i+3

Answer 4

\[3\iota \left( 8-\iota \right) =24\iota-3\iota ^{2}=24\iota-3\left( -1 \right)=24\iota+3 \]

Answer 5

for the second one distribute the - sign to the terms in te parentheses and then get rid of the parentheses and simply add and subtract

Answer 6

10-2i

Answer 7

correct

Answer 8

Thank you both very much.