设原来的两位数十位是 x ,则个位是 2x
10x + 2x = 20x + x - 36
12x = 21x - 36
21x - 12x = 36
9x = 36
x = 36÷9
x = 4
十位 = 2x = 8
个位 = x = 4
所以这个两位数是 84
设原来的两位数十位是 x ,则个位是 2x
10x + 2x = 20x + x - 36
12x = 21x - 36
21x - 12x = 36
9x = 36
x = 36÷9
x = 4
十位 = 2x = 8
个位 = x = 4
所以这个两位数是 84