№1
-7(-4х+3)+2(3х-7) = 28х-21+6х-14 = 34х - 35
№2
9(8-7а)-8(6а-9) = 72-63а-48а+72 = 144 - 111а
№3
4,5(-8у-7)-3,9(6-9у) = -36у-31,5-23,4+35,1у =
= -0,9у - 54,9
№1
-7(-4х+3)+2(3х-7) = 28х-21+6х-14 = 34х - 35
№2
9(8-7а)-8(6а-9) = 72-63а-48а+72 = 144 - 111а
№3
4,5(-8у-7)-3,9(6-9у) = -36у-31,5-23,4+35,1у =
= -0,9у - 54,9