What are the common multiples of 9,6 and 4 I have a question it says use one common denominator to find these sums and it says 3 over 4 + -5 over 6 + -3 over 8. Help?
The fractions you're adding just have the denominators of 4, 6 and 8
We only need worry about the 6 and the 8 because 4 is already a factor of 8
So 8 factors as 2^3 and 6 factors as 2 x 3
So...taking the highest power of each different factor, the common denominator = 2^3 x 3 = 8 x 3 = 24
So we have
3/4 = 18/24
-5/6 = - 20/24 and
-3/8 = -9/24
Now...just add.subtract the fractions on the right side of the equal signs...
The fractions you're adding just have the denominators of 4, 6 and 8
We only need worry about the 6 and the 8 because 4 is already a factor of 8
So 8 factors as 2^3 and 6 factors as 2 x 3
So...taking the highest power of each different factor, the common denominator = 2^3 x 3 = 8 x 3 = 24
So we have
3/4 = 18/24
-5/6 = - 20/24 and
-3/8 = -9/24
Now...just add.subtract the fractions on the right side of the equal signs...