Question

Which expression is equivalent to (4 + 6i)2?

Answer 1

if you mean
`(4+6i)^2` then
remember that
`i=√(-1)` and that
`i^2=-1`
just treat 'i' as a variable for the expansion part

`(4+6i)^2=`
`(4+6i)(4+6i)=`
`(4*4)+(6i*4)+(4*6i)+(6i*6i)=`
`16+24i+24i+36i^2=`
`16+48i+36(-1)=`
`16+48i-36=`
`-20+48i`
you didn't give us the expressions so you will have to see which one of them is equivilent ot -20+48i

Answer 2

`\bf \textit{recall that }i^2=-1\\\\ -------------------------------\\\\ (4+6i)^2\implies (4+6i)(4+6i)\implies 16+24i+24i+36i^2 \\\\\\ 16+48i+36(-1)\implies 16+48i-36\implies -20+48i`