Question

considere os números complexos z=2+3i e w=2-5i, determine z.w. ajuda gente por favor

Answer 1

(2 + 3i)(2 - 5i) = 4 - 10i+ 6i - 15i² = 4 - 4i -15(-1) = 19 - 4i

Answer 2

$Ola'~~\mathbb{JUU} \\ \\ z.w=(2+3i)(2-5i) \\ \\ z.w=2.2-2(5i)+2(3i)-3i(5i) \\ \\ z.w=4-10i+6i-15i\²~~--\ \textgreater \ lembre~que~[i\²=-1] \\ \\ z.w=4-4i-15(-1) \\ \\ z.w=4-4i+15 \\ \\ \boxed{\boxed{z.w=19-4i}} \\ \\ \mathbb{iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii}\\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Espero~ter~ajudado!!$