How do you simplify $(9-5i)(7+4i)$ ?

Question

2361 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-02-02T10:40:49

Solve as normal, then replace the $i$ s

Foil
$=63+36i-35i-20i^2$

Combine Like Terms
$=63+i-20i^2$

Substitute in $i^2 = -1$
$=63+i+20$

Add Numbers
$83+i$

How do you simplify (9-5i)(7+4i)(9-5i)(7+4i)?