Adding & Subtracting Fractions
In order to add or subtract fractions, the denominators
have to be the same.
When the denominators are the same, then we can add/subtract.
Step 1: Find the Lowest Common Denominator (LCD)
Find the LCD by figuring out the Least Common Multiple (LCM). For example:
2 • 3 = 6 Thus the LCD = 6
Step 2: Multiply numerator and denominator by the
number you used to make the LCD.
Here we use “3” because ← Here we use “2” because 2 • 3 = 6
After we multiply everything, we end up with this:
Step 3: Add/Subtract numerators together and keep denominators the same.
Reduce if possible; if not, you are done!
When multiplying fractions, multiply straight across.
Reduce if possible.
Both have a factor of six that cancels out.
Flip & Multiply
We flip the second fraction, then multiply straight across. Then reduce, both have a factor of 2 that cancels out.
We can ONLY clear fractions when there is an equal sign.
Step 1: Find the LCD
Step 2: Multiply everything by LCD, clear the fractions, & then reduce:
Simplify and Solve 6 + 4X = 1
Subtract 6 from both sides
Divide by 4 on both sides to isolate the X: