Answer :

4x - 2y = 14
y = 0.5x -1

Get just one variable on one side for both equations.

4x - 2y = 14 ⇒ 4x = 2y + 14 ⇒ 4x - 14 = 2y
y = 0.5x - 1 ⇒ x - 2 = 2y

Use the transitive property and then solve for x.

x-2 = 4x-14
12 = 3x
x = 4

Edit: Apprently I didn't use substitution. Oops! Sorry...
4x-2(1/2x-1)=14
4x-x+2=14. 1=1/2(4)-1
3x+2=14. 1=2-1
3x=12. 1=1
X=4
Y=1/2(4)-1
Y=2-1 Y=1