Y-23=35-28 16+y=81-24 19+y=34+18

a, y-23=35-28

y-23=7

y=7+23

y=30

b, 16+y=81-24

16+y=57

y=57-16

y=41

c, 19+y=34+18

19+y=52

y=52-19

y=33

(Học tốt nhé!)

\[\begin{array}{l}a)\,y - 23 = 35 - 28\\\,\,\,\,\,y - 23 = 7\\\,\,\,\,\,y = 7 + 23\\\,\,\,\,\,y = 30\\b)\,16 + y = 81 - 24{\rm{ }}\\\,\,\,\,\,\,16 + y\,{\rm{ = }}\,{\rm{57}}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,y = 57 - 16\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,y = 41\\c)19 + y = 34 + 18\\\,\,\,\,19 + y = 52\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,y = 52 - 19\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,y = 33\end{array}\]