No, the denominators have to be the same.
First find the lowest common denominator and then adjust the fractions accordingly before subtracting the numerators
I learned to always change the denominators before adding or subtracting the numerators. You must always have a common denominator before adding or subtracting.
Because think of like fractions as the same things.. you can subtract halves from halves for example, but what does it mean to take away a half from a third?By converting them into like fractions, we can add or subtract them easily.
because it would be diffcult to understand.[you don't add or subtract the demonters]
To multiply two fractions, the numerator (top part) of the result is the product of the numerators, and the denominator (bottom part) of the result is the product of the denominators. There is no need to convert to a common denominator first; this is only necessary to add, subtract, or compare fractions. For example, 1/2 x 5/7 = (1x5) / (2x7) = 5/14. Note that it is easier to do any simplifications BEFORE doing the actual multiplication.
First find the lowest common denominator and then adjust the fractions accordingly before subtracting the numerators
I learned to always change the denominators before adding or subtracting the numerators. You must always have a common denominator before adding or subtracting.
Because think of like fractions as the same things.. you can subtract halves from halves for example, but what does it mean to take away a half from a third?By converting them into like fractions, we can add or subtract them easily.
because it would be diffcult to understand.[you don't add or subtract the demonters]
The denominators must be the same before you can add or subtract fractions.
To multiply two fractions, the numerator (top part) of the result is the product of the numerators, and the denominator (bottom part) of the result is the product of the denominators. There is no need to convert to a common denominator first; this is only necessary to add, subtract, or compare fractions. For example, 1/2 x 5/7 = (1x5) / (2x7) = 5/14. Note that it is easier to do any simplifications BEFORE doing the actual multiplication.
So that you only have to add/subtract the numerator which makes it much easier.
You DO need a common denominator to add, subtract, or compare fractions. You DO NOT need a common denominator to multiply or divide fractions.
Before you can add or subtract, both fractions must have the same denominator, andmaking that change without changing the value of either fraction is your job. The bestchoice for a 'common' denominator is usually the least common multiple of the originaldenominators.
You multiply the numerators, and the denominators, separately. a/b x c/d = ac/bd.It often helps to do any simplification before you do the actual multiplication.
Because common denominators allow adding and subtracting of numerators. Improper fractions also have simplified rules over mixed numbers when performing multiplication and division.
Because the answers will be wrong when adding or subtracting them if they don't have a common denominator.