Question

Multiply (2 - 71)(-1 + 41)?
26 + 151
-2 - 281
26 + i
-30 + 151

Answer 1

For this case we must simplify the following expression:

`(2-7i) (- 1 + 4i)`

Applying distributive property we have:

`(2) (- 1) + (2) (4i) + (- 7i) (- 1) + (- 7i) (4i) =`

We have to:

`+ * - = -\\- * - = +`

So:

`-2 + 8i + 7i-28i ^ 2 =`

We add similar terms:

`-2 + 15i-28i ^ 2 =`

By definition we have:
`i ^ 2 = -1`

`-2 + 15i-28 (-1) =\\-2 + 15i + 28 =`

Different signs are subtracted and the sign of the major is placed:

`26 + 15i`

Answer:

`26 + 15i`