Master Fractions: Solve Quickly All Fraction Problems

in this lesson we're gonna focus on adding and subtracting fractions let's say if we have 3/5 plus 4/7 how can we add these two fractions well here's a simple technique first multiply five and seven this will give you a common denominator of 35 next multiply three and seven three times seven is twenty-one and also there's a plus in between multiply 5 times 4 which is 20 21 plus 20 is 41 so the answer is 41 divided by 35 let's try another example let's say if we want to subtract 7 over 8 minus 2 over 9 let's use the same technique let's multiply the two denominators 8 + 9 which is 72 and then the next one it's gonna be 7 times 9 which is 63 minus 8 times 2 which is 16 now let's subtract what is 63 minus 16 this is gonna be 47 now 47 is not divisible by 2 nor is it divisible by 3 so this is it that's the final answer so now you know how to add or subtract two fractions now what if we want