SOLUTION: x+y=5 3x-y=7

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Question 80645: x+y=5
3x-y=7

Found 2 solutions by stanbon, praseenakos@yahoo.com:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
x+y=5
3x-y=7
---------
Add the two equations to get rid of the y-terms:
4x=12
x=3
------
substitute that into one of the original equation and solve for Y:
3+y=5
y=2
---------
Solution: x=3,y=2
======================
Cheers,
Stan H.

Answer by praseenakos@yahoo.com(507) (Show Source):
You can put this solution on YOUR website!
QUESTION:

x+y=5
3x-y=7

ANSWER:

x+y=5 --------------------(1)

3x-y=7 --------------------(2)

Add Equation (1) and (2)

==> x + y + 3x - y = 5 + 7

==> x + 3x + y - y = 12

==> 4x + 0 = 12

==> 4x = 12

Divide both sides of the equation by 4, then we have,

4x/4 = 12/4

==> x = 3

Now substitute the value of x in any of the given equation.

lets take equation (1)

(1)==> 3 + y = 5

Subtract 3 from both sides of the equation,

==> 3 + y - 3 = 5 - 3

==> y = 2

So the solution is x = 3 and y = 2
To check the solution, substitute these values in the given equations, it will satisfy the equation.

Hope you understood.

Regards.

Praseena.