Question

How do I add and subtract unlike fractions

Answer 1

You have to make the denominator (bottom number of a fraction) of each fraction the same.
For example:
1/2 + 2/3
To make the denominator the same, multiply the denominator of the first fraction (2) by the denominator of the second fraction (3), then do the opposite with the second fraction :
1/2 + 2/3
Multiply both TOP and BOTTOM by 3:
3/6
Multiply both TOP and BOTTOM by 2:
4/6
As you can see the denominator of both fractions are now the same, which means we can add them:
3/6 + 4/6 = 7/6

And you would use this same method for subtraction too!
Hope this helped :)

Answer 2

You add and subtract unlike fractions by finding a common denominator, which is basically the LCM (Least Common Multiple) of the two numbers. Then, once the two fractions have the same base, you can straight up add the numerators, and if possible, simplify. Here are some examples:
1/5 + 3/10 = ?
Denominators = 5, 10
What is the LCM?
=> 10
Therefore...
1/5 × (2/2) + 3/10 = ? (The paranthesis next to 1/5 shows how we are creating a common denominator)
2/10 + 3/10 = ?
= 5/10
= 1/2 (Simplify)
Hope this helped and have a phenomenal day!