. Solve for x and y : 23x + 35y = 209 35x + 23y = 197

 23x + 35y = 209

35x + 23y = 197

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58x + 58y = 406

58( x + y) = 406

x + y = 406/58

x + y = 7 

y = 7 - x --------------1

now,

23x + 35y = 209

35x + 23y = 197

-       -            -

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-12x + 12y = 12

12 ( -x + y) = 12

y - x = 12/12

y - x = 1 ------------2 

now, put the value of y frm eq. 1

7 - x - x = 1

7 - 2x = 1

-2x = -6

2x = 6

x = 3

now, put the value of x in eq. 2

y - 3 = 1

y = 4

therefore x = 3 nd y = 4.... ans