Question 34638
2x-4y=7                    
(4x+2y=9)*2

2x-4y=7    
8x+4y=18
Adding
10X = 25
X = 25/10 = 5/2

Substitute this into any of the above equations to get the value of Y
Substituting in the first Equation
{{{2(5/2) -4y = 7}}}
{{{5 -4y = 7}}}
Re-Arranging
5-7 = 4y
-2 = 4y
Dividing by 4 on both sides
y = -2/4 
Y = -1/2