Question #91958
1 Answer
Jun 27, 2017
Explanation:
#"expand " (7+i)(3-4i)" using FOIL"#
#color(orange)"Reminder " i^2=(sqrt(-1))^2=-1#
#rArr(7+i)(3-4i)#
#=21-28i+3i-4i^2#
#=25-25ilarrcolor(red)" in standard form"#