Which expression gives the x-coordinate of the solution of the system? {5x+3y= -18 {2x- 4y= -28}

To find the the expression that gives the value of  we are going to proceed as follows: 
equation (1)
equation (1)

Step 1. solve for  in equation (2)



equation (3)

Step 3. Replace equation (3) in equation (1) and solve for 







We can conclude that the expression that gives the value of  is: