Răspuns:
(a x7-50) :30=3
a x7-50= 30 x3
ax7-50=90
ax7=90+50
ax7=140
a=140:7
a=20
20
Explicație pas cu pas:
(a×7-50):30=27:9
(a×7-50):30=3
(a×7-50)=3×30
(a×7-50)=90
(a×7)=90+50
a×7=140
Verific:
(20×7-50):30=
(140-50):30=
90:30=
3✔
