A={1,2,3,4} R={(a,b),(c,d)} 2a+3b=4c+5d=α let 2a={2,4,6,8}4c={4,8,12,16} 3b={3,6,9,12}5d={5,10,15,20} \;2 {\text{a}}+3 {\text{b}}={\begin{cases}5 & 8 11 14 \\ 7 & 10 13 16 \\ 9 & 12 15 18 \\ 11 & 14 17 20 \}} 4 {\text{c}}+5 {\text{d}}{\{\text{table} 9 14 19 24 \\ 13 & 18\end{cases} . . ; 17,22 . . . . ; 21,26 . . . . \}}Possible value of α=9,13,14,14,17,18 Pairs of {(a,b),(c,d)}=6