1 câu trả lời
xx + x + 5 = 125
x0 + x + x + 5 = 125
x X 10 + x + x = 125 - 5
x X 10 + x + x = 120
x X ( 10 + 1 + 1 ) = 120
x X 12 = 120
x = 120 : 12
x = 10
xx + x + 5 = 125
x0 + x + x + 5 = 125
x X 10 + x + x = 125 - 5
x X 10 + x + x = 120
x X ( 10 + 1 + 1 ) = 120
x X 12 = 120
x = 120 : 12
x = 10