Question

solve 47 X + 31 y = 36, 31 x + 47 Y = 15

Answer 1

47x+31y=63(eqn 1)
31x+47y=15(eqn 2)

adding both eqn,we get

78x+78y=78 dividing this eqn by 78,we get

x+y=1 (be it eqn 3)subtracting eqn 1 and eqn 2,we get

16x-16y=48

dividing this eqn by 16, we get

x-y=3(be it eqn 4)

using elimination method for eqn 3and eqn4x+y=1x-y=32x=4x=2putting value of x in x+y=1,by solving we gety=-(negative)1
thereforex=2y=-1