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 solve for x and y :

47x + 31y = 63

31x + 47y = 15

wehave,  47x + 31y =63  ...............(1)

and          31x +47Y =15..................(2)

adding (1) and (20 we get

                                      78x + 78y =78 

dividing it by 78 we get 

                                         x + y =1.................. (3)

again  subtacting (1) and (2) we get

                                         16x - 16y= 48

dividing it by 16 we get

                                           x - y = 3...............(4)

Now, adding (3) and (4) we get

                                                  2x = 4                                                                                                                                                                                                                     Hence x = 2

Putting x  in (4) we get 

                                      2 -y =3    

                                           Hencey =-1

                      Therefore x = 2,  y =-1

  • 23
View Full Answer

IT IS A DIFFERENT METHOD IN WHICH WE WILL FIRST ADD BOTH TERM N THEN SUBTRACT BOTH TERMS

ON ADDITION OF BOTH EQUATIONS

47x+31y=63

31x+47y=15

we will get

78x+78y=78 (1)

divide equation (1) throughout by 78 then we will get

x+y=1 (2)

now subtract both the equations

47x+31y=63

31x+47x=15

we will get

16x-16y=48 (3)

divide equation (3) throughout by 16 we will get

x-y=3 (4)

now we can subtract equation (2) from (4) i.e.

x+y=1

x-y=3

we will get

2x=4

therefore x=2

since x+y=1

therefore put the value of x in above equation we will get

2+y=1

therefore y=-1

so our ans is

x=2 and y=-1

VERIFICATION

47*2+31*(-1)=63

HOPE THIS WILL HELP YOU

  • 12
It's a piece of cake to solve these kind of sums. 
  • -13
just use elimination meathods these r easy one frnd just try 
  • -10
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