Răspuns :
(520-516)×a:(3×3+8:8×21)+398=410
4×a:(9+21)+398=410
4×a:30+398=410
4×a:30=410-398
4×a:30=12
4×a=12×30
4×a=360
a=360:4
a=90
Răspuns:
(520-516)×a:(3×3+8:8×21)+398=410
4×a:(9+21)+398=410
4×a:30=410-398
4×a:30=12
4×a=30×12
4×a=360
a=360÷4
a=90