How do you solve the following linear system: x + y = 6 , x = y + 2 x+y=6,x=y+2?

1 Answer
Nov 19, 2015

Substitute xx by using yy or vice versa.
Solve it like a normal equation
Solve for the other variable

Explanation:

1: x + y = 61:x+y=6
2: x = y + 22:x=y+2

The second equation helps us a lot here, since xx is isolated from yy and the constant. The second equation states that xx can be written as y + 2y+2, since x = y + 2x=y+2. Put this expression into equation number 1.

1: color(red)(y + 2) + y = 61:y+2+y=6
NOTE: The red symbolizes a xx.

1: 2y = 6 - 21:2y=62
1: 2y = 41:2y=4
1: y = 21:y=2

Put the value of yy into the first equation.
x + y = 6x+y=6
x + 2 = 6x+2=6
x = 6 - 2x=62
x = 4x=4

Conclusion: x = 4x=4 and y=2y=2