а) -40* ( x - 16 ) = -440
x - 16= -440:(-40)
х-16=11
х=11+16
х=27
-40* (27-16) = -40*11=-440
б) (40 − 9x) ⋅ 9 = 441
40-9х=441:9
40-9х=49
9х=40-49
9х=-9
х=-9:9
х=-1
(40 − 9*(-1)) ⋅ 9 =(40-(-9))*9=(40+9)*9=49*9=441
в) 5/12y - 3/6 = 1/3
5/12у=1/3+3/6
5/12у=2/6+3/6
5/12у=5/6
у=5/6:5/12
у=5/6*12/5
у=2
2*5/12-3/6=5/6-3/6=2/6=1/3