50 + 50 + 70 + 20 + 30 + 80 + 700=?
20 + 60 + 50 + 80 + 90 + 10 + 50 + 60 x 10
x + 20 = 50 + 80
x + 50 = 80 + 20
(60-50)+(40-30)+(90-80)-20=????
10+20+30+40+50+60+70+80+90+100=..................
10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 +100 + 200 + 300 =
100-20-20+50+60-70-100+90-80-10=?
ai giải nhanh nhất mình tich cho!
tìm x :
x + 20 - 10 = 110
x + 80 - 50 = 100