Change any mixed numbers to improper fractions by multiplying the denominator by the whole number and adding it to the numerator.
Re-copy the problem underneath the original, leaving the numerators and denominators blank. Include a blank fraction after the equals sign so that you have three total.
Find the smallest number that both denominators can go into evenly - this is the LCD. Then, write the LCD in each blank denominator.
Look at each original denominator and figure out what you would need to multiply that denominator by to make the LCD. Next, multiply the numerator above it by the same number and write the result in the blank numerator below.
Perform the addition or subtraction problem on the new numerators. Then, write the answer over the LCD in the answer fraction.
Simplify the answer. If the numerator and denominator share a common factor, divide both of them by that number.