47x + 31y = 63

31x + 47y = 15

x = 2, y = - 1

Step-by-step explanation:

47x + 31y = 63 ... eqn 1

31x + 47y = 15 ... eqn 2

multiply eqn 1 by 47 to get eqn 3 and multiply eqn 2 by 31 to get eqn 4 ...

=> 2209x + 1457y = 2961 ... eqn 3

=> 961x + 1457y = 465 ... eqn 4

subtract eqn 4 from eqn 3

=> 1248x = 2496

=> x = 2

subst x = 2 in eqn 1

=> 94 + 31y = 63

=> 31y = - 31

=> y = - 1