(2.61-4х):0.03+4.6=90
(2.61-4х):0.03=90-4.6
(2.61-4х):0.03=85.4
2.61-4х=85.4*0.03
2.61-4х=2.562
-4х=2.562-2.61
-4х=-0.048
х=-0.048:(-4)
х=0.012.
-9,2+b+7,4+5,72+(-7,4)=-9,2+b+7,4+5,72-7,4=-3,48+b
-3,48+(-4,3)=-3,48-4,3=-7,78
Ответ:24
Пошаговое 2×4=8 16+8=24(к.к.)