Student puzzled

( 0.17 - 3.5j ) ( 1.12 - 0.91j )

I'm assuming you want to "expand" this??

Start by multiplying .17 * 1.12 = .1904

Then mutiply (-3.5j) * (1.12) = -3.92j

Then multiply (.17) * (-.91j) =  -.1547j

Finally , multiply (-3.5j) * (-.91j) = 3.185j²

So putting this all together, we have

3.185j² -3.92j - .1547j + .1904 =

3.185j² - 4.0747 + .1904j