SOLUTION: For problems 7 through 9, solve the system of equations using ADDITION to eliminate one variable. If the system has no solution, indicate that is is inconsistent. If it has infin

Algebra ->  Expressions-with-variables -> SOLUTION: For problems 7 through 9, solve the system of equations using ADDITION to eliminate one variable. If the system has no solution, indicate that is is inconsistent. If it has infin      Log On


   

Question 359621: For problems 7 through 9, solve the system of equations using ADDITION to eliminate one variable. If the system has no solution, indicate that is is inconsistent. If it has infinite solutions, indicate that it is dependent. If the system has a solution, CHECK YOUR ANSWER.
8.
x+y=3
2y=10-2x
CHECK (if possible)
Pleeeaase help me!! I am so stuck I don't know what to do!! Thank you! :)
Answer by Jk22(389) About Me  (Show Source):
You can put this solution on YOUR website!
The system is :

x + y = 3
2x+2y = 10

if we add 2 times the 1st equation plus minus the 2nd we eliminate x and y, and get the equation :

0 = 6 - 10 = -4

which is impossible. Hence the system has no solution and is inconsistent.


By substitution we would have got : x = 3 - y and

6 - 2y + 2y = 10 => 6 = 10 which is wrong, hence no solution.