4/5-1/10=7/10
First, you have to find a common denominator (which is 10 in this case): 5x2=10, and you do the same to the numerator: 4x2=8
This turns the equation into: 8/10-1/10
Since they have the same denominator, you can just subtract the numerator: 8/10-1/10=7/10
