Question

5 x + 4y = 12 x - 3y = 5​

Answer 1

5x  +  4y = 12

x - 3y = 5                    ⇒   x = 3y + 5

5(3y + 5) + 4y = 12

15y + 25 + 4y = 12

15y + 4y = 12 - 25

19y = - 13

y = - 13/19

x - 3y = 5

x - 3( - 13/19) = 5

x + 39/19 = 5

x = 5 - 39/19

x = 95/19 - 39/19

x = 56/19

(  56/19,  - 13/19  )