Here are the Steps in solving systems of equation using Substition method
1. In either equation, solve for one variable in terms of the other.Using 2x+y=104, solve y in terms of x.

2x+y=104
y = -2x + 104


2. Substitute -2x + 104 for y in the other equation 0.5x-2y=17. Solve x.

0.5x-2(-2x+104)=17 
Apply distributive property to simplify the equation
0.5x - 2(-2x) - 2(104) = 17
0.5x + 4x - 208 = 17
4.5x - 208 = 17
4.5x = -225 
Divide both sides by 4.5 to solve for x



3. Substitute the result from step 2 in either equation. Solve for the other variable y.

 2x+y=104 , x = 50
2(50) + y = 104
100 + y = 104


4. Check the solution in both original equations.

2x+y=104 when x=50 and y=4
2(50) + 4 = 104
100 + 4 = 104
104 = 104 ----------->> True


0.5x-2y=17  when x=50 and y=4
0.5(50)-2(4)= 17  
25 - 8 = 17
17 = 17 --------->> True


Therefore the solution of the systems of equation is x = 50 and y = 4