Thursday, June 1, 2017

How To Add Fractions With Variables In The Numerator And Denominator



let's try to evaluate 7and 6/9 minus 3 and 2/5. so like always, i like toseparate out the whole number parts from the fractional parts. this is the same thing as 7plus 6/9 minus 3 minus 2/5. and the reason why i'msaying minus 3 minus 2/5


How To Add Fractions With Variables In The Numerator And Denominator, is this is the same thingas minus 3 plus 2/5. and so you distributethe negative sign. you're subtracting a 3, andthen you're subtracting the 2/5. and so now we can worryabout the whole number


parts, 7 minus 3. well, 7 minus 3 isgoing to give us 4. so that's going to give us 4. and then we're goingto have 6/9 minus 2/5. so let me think aboutwhat 6/9 minus 2/5 are. 6/9 minus 2/5, well,we're going to have to find a common denominator. so this is going tobe the same thing. and i think the leastcommon multiple of 9 and 5


is going to be 45. literally, you then multiply. they have no common factors. so it's going to be over 45. to go from 9 to 45, ihave to multiply by 5. so i'm going to have tomultiply the numerator by 5. so 6 times 5 is 30. then i'm going to subtract. to go from 5 to 45, ihad to multiply by 9.


so i have to multiplythe numerator by 9 if i don't want tochange the value. so 2 times 9 is 18. and 30/45 minus 18/45 isgoing to be something over 45. 30 minus 18 is 12. if i subtract these twofractions right over here, i get 12/45. so it's 4 plus 12/45. or if we wanted to writeit as a mixed number,


this is equal to 4 and 12/45. but we're not done yet. we can simplify this further. 12 and 45 have common factors. they're both divisible by 3. actually, they're bothdivisible by-- well, i think we can dividemore after that. so let's see. if we divide the numerator by3 and the denominator by 3,


we end up with 4. and 12 divided by 3 is 4. and 45 divided by 3 is 15. 4 and 4/15. and actually, we're done. these two can't besimplified anymore.


No comments:

Post a Comment

Up