It's 5x - 14 = 6.
let x be the number.
Since 14 is subtracted from 5 times a number. It is not automatically 14 - 5. you have to consider that 14 is actually deducted from the product of 5 and a number.
5x - 14 = 6
5x = 6 + 14
5x = 20
5x/5 = 20/5
x = 4
To check:
5x - 14 = 6
5(4) - 14 = 6
20 - 14 = 6
6 = 6