Question

Solve 3x+2y=14 and -x+4y=7 by elimination method

Answer 1

Let 3x+2y=14......(I) and -x+4y=7.....(ii)

Eq(I)× -1 ---> -3x-2y=-14

Eq (ii) ×3 ---> -3x+2y=21

+. -. -

-------------------

(Sub). -14y=-35

y=-35/-14

y= 5/2

Putting y=5/2 in eq (ii)

-x+4×5/2= 7

=> -x= 7-10

=>-x= -3

=>x= 3

Answer 2

3x + 2y= 14 ( -x + 4y = 7) × 3

-3x + 12y=21

Now,

3x + 2y= 14

- 3x +12y= 21

____________

14 y= 35

y= 35/14

Similarly .. x = 3