Question

Answer 1

( 12/15 + 18/15 ) + ( 9/13 + 4/13 )

= 2 + 1

= 3

Answer 2

\(\dfrac{12}{15}+\dfrac{9}{13}+\dfrac{18}{15}+\dfrac{4}{13}\)

\(=\left(\dfrac{12}{15}+\dfrac{18}{15}\right)+\left(\dfrac{9}{13}+\dfrac{4}{13}\right)\)

\(=2+1\)

\(=3\)