`4 5/11+2 9/13+3 6/11+4 4/13`
`= 49/11+35/13+39/11+56/13`
`= (49/11+39/11)+(35/13+56/13)`
`= 88/11+91/13`
`= 8+7`
`= 15`
`4 5/11 + 2 9/13 + 3 6/11 + 4 4/13`
`=(4 5/11 + 3 6/11)+(2 9/13 + 4 4/13)`
`=7 11/11 + 6 13/13`
`=8+7=15`
= 49/11 + 35/13 + 39/11 + 56/13
= ( 49/11 + 39/11) + (35/13 + 56/13)
= 88/11 + 91/13
= ...
\(=\dfrac{49}{11}+\dfrac{35}{13}+\dfrac{39}{11}+\dfrac{56}{13}=\left(\dfrac{49}{11}+\dfrac{39}{11}\right)+\left(\dfrac{35}{13}+\dfrac{56}{13}\right)=8+7=15\)