Answer :
distributeiv poepty
a(b+c)=ab+ac
remember that (-) times (-)=(+)
and (+) TIMES (-)=(-)
SO
-7(-5v-3u+4)=(-7)(-5v)+(-7)(-3u)+(-7)(4)=35v+21u-28
a(b+c)=ab+ac
remember that (-) times (-)=(+)
and (+) TIMES (-)=(-)
SO
-7(-5v-3u+4)=(-7)(-5v)+(-7)(-3u)+(-7)(4)=35v+21u-28