Răspuns:
a-7×6=10+9
a-42=19
a=42+19
a=61
a+6×8=9×10
a+48=90
a=90-48
a=42
9×9-a=100-7×7
81-a=100-49
81-a=51
a=30
a-6×4=9×3+8×2
a-24=27+16
a-24=43
a=43+24
a=67
