(x+5-2i)(x+5+2i) how do I work this out I can not remember please show me how to find the answer thanks!

Asked on by primrose44

1 Answer | Add Yours

Top Answer

embizze's profile pic

embizze | High School Teacher | (Level 2) Educator Emeritus

Posted on

Expand `(x+5-2i)(x+5+2i)`

We use the extended distributive property:



`=x^2+10x+25-4i^2` (but `i=sqrt(-1)=>i^2=-1` so)


Thus `(x+5-2i)(x+5+2i)=x^2+10x+29`

We’ve answered 319,863 questions. We can answer yours, too.

Ask a question