Question

Reduce answers as much as possible by finding common factors

#1. 2/5+ 2/7
#2. 4/28 - 7/9
#3. 3 1/3 +4 7/8

PLEASE PLEASE help if u can !! and if u can show how u did it , thank you!

you dont have to answer all if u dont want to atleast just one

Answer 1

You can only add or subtract fractions that have THE SAME DENOMINATOR.

If the two fractions do not have the same denominator :

they must be REDUCED TO THE SAME DENOMINATOR.

2/5 + 2/7 =

common denominator:5*7=35

2/5 commun denominator 35 = (2*7)/(5*7)= 14/35

2/7 commun denomintor 35 = (2*5)/(7*5)= 10/35

add 2/5 + 2/7 = 14/35+10/35 = 24/35

4/28 - 7/9

here the common denominator (9*28) = 252 is the smallest

4/28 commun denominator 252 = (4*9)/(7*28)= 36/252

7/9 commun denominator 252 = (7*28)/(9*28)= 196/252

4/28 - 7/9 = 36/252-196/252= -160/252 =simplify (by 2) = 49/63

3 1/3 + 4 7/8

transform into an improper fraction :

3 1/3 =[(3*3)+ 1/3]/3 = (9+1)/3 = 10/3

4 7/8 =[(4*8)+ 7/8] = (32+7)/8 = 39/8

10/3 + 39/8

common denominator: 3*8 =24

10/3 commun denominator 24 = (10*8)/(3*8)= 80/24

39/8 commun denominator 24 =(39*3)/8 =117/24

3 1/3 +4 7/8 = 10/3 + 39/8 = 80/24+117/24= 197/24