You need to know the least common denominator (LCD) of 4 and 30 if you want to add or subtract two fractions with 4 and 30 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 4 and 30 is 60.
Here is a math problem example where you need to know the LCD of 4 and 30 to solve:
3/4 + 2/30 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
60/4 = 15
60/30 = 2
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 15 = 45
2 x 2 = 4
Step 3) Put it all together to solve the problem:
45/60 + 4/60 = 49/60
= 3/4 + 2/30 = 49/60
It's that easy! Once again, the lowest common denominator (LCD) of 4 and 30 is as follows:
60
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