Q. Simplify the following expressions completely. a) 5(8+7i) Preview b) (−7−4i)(3+2i)
Distribute 5: Distribute the 5 to both terms inside the parentheses for expression a).5×8+5×7i=40+35i
Multiply using FOIL: Just multiply the numbers for expression b), using FOIL (First, Outer, Inner, Last).(−7)(3)+(−7)(2i)+(−4i)(3)+(−4i)(2i)=−21−14i−12i−8i2
Use i2=−1: Remember that i2 equals −1. So, −8i2 becomes −8(−1) which is +8.
Combine like terms: Combine like terms for expression b). −21+8−14i−12i=−13−26i
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