2у-45=45,
2у=45+45=90,
2у=90 (:2)
у=45.
72+7а=86,
7а=86-72=14,
7а=14 (:7)
а=2.
11(60+а)=847,
660+11а=847,
11а=847-660=187,
11а=187 (:11)
а=17.
(48-z)+19=37,
49+19=37+z,
z+37=68,
z=68-37=31,
z=31.
2у-45=45,
2у=45+45=90,
2у=90 (:2)
у=45.
72+7а=86,
7а=86-72=14,
7а=14 (:7)
а=2.
11(60+а)=847,
660+11а=847,
11а=847-660=187,
11а=187 (:11)
а=17.
(48-z)+19=37,
49+19=37+z,
z+37=68,
z=68-37=31,
z=31.