For the following system, use the second equation to make a substitution for y in the first equation.
2x+y=5
Y+3=2x
Here are the choices:
2x+2x-3=5
2x+3-2x=5
2x+2x+3=5

Question

For the following system, use the second equation to make a substitution for y in the first equation. 
2x+y=5
Y+3=2x
Here are the choices: 
2x+2x-3=5
2x+3-2x=5
2x+2x+3=5

radar · Answer

O.K.  The 2nd equation is 2x = y + 3   we can substitute for the 2x in the 1st equation:

(y + 3) + y = 5     Now it is just algebra
2y + 3 = 5       after combining similar terms
2y = 5 - 3        subtracting three from both side.  Please continue with the solution.