Question 659773
Starting with,
2x+ y+4
 x-3y+9

Multiply the second equation by -2
-2(x-3y+9)
-2x + 6y - 18
Add this equation to the first equation
2x + -2x + y + 6y + 4 + -18
Combine like terms
7y - 14 = 0
7y - 14 + 14 = 0 + 14
7y = 14
7y/7 = 14/7
y = 2

Multiply the first equation by 3
3(2x+y+4)
6x + 3y + 12
Add to the second equation
6x + x + 3y + -3y + 12 + 9
Combine like terms
7x + 21 = 0
7x + 21 - 21 = 0 -21
7x = -21
7x/7 = -21/7
x = -3