X-y=-1 x+y=9

Question

Solve system of equations. Check the solution

Answer 1

Hi Zolan, to solve this system of equation, add the second equation to the first equation. This will eliminate the y variable, and you can solve for the x variable.

 

Solve for x:

 

x  - y = -1

x + y =  9

------------

2x      = 8

 

Divide both sides by 4 giving:

 

x = 4

 

Solve for y:

 

Substitute for x in the second equation to find the value for y.

 

4  +  y  = 9

 

Subtract 4 from both sides of the equation gives:

 

y = 5

 

Solution: x = 4, y = 5

 

Check:

 

substitute for x and y in first equation:

 

4 - 5 = -1

 

-1 = -1, values check.

 

Questions?

Answer 2

X-y=-1 x+y=9
Solve system of equations. Check the solution

 

 

add the equations; you'll end up with

 

2x=8 which gives x=4

 

substitute x in any equation, say, 1st:

 

4-y=-1  that is y=5

 

now, check for me ... :)