Explanation:
8x + 14y = 4 ...1
-6x - 7y = -10 ...2
...2 × 2 in 2 sides of the equation
-12x -14y = -20 ...3
...1 + ...3
8x + 14y +(-12x -14y) = 4 +(-20)
8x + 14y - 12x -14y = 4 - 20
-4x = -16
x = (-16)/(-4)
= 4
replace x in ...1 or ...2 you will reserve y value
and answer in the term of (x,y)