three times a number.....3x...with the x representing the number ten less....3x - 10 is the same as...means = that number (x) increased by 4....x + 4 so we have 3x - 10 = x + 4...
3x - 10 = x + 4 3x - x = 4 + 10 2x = 14 x = 14/2 x = 7....and that number is 7