Question

What is the x-coordinate of the solution of the following system of equations?

3x + y = 6
x - y = 6

-3
0
3

I believe the answer is 0 ?

Answer 1

how is that answer zero?
SHOW YOUR SOLUTION

Answer 2

x - y = 6...-y = -x + 6.....y = x - 6

3x + y = 6
3x + x - 6 = 6
4x = 6 + 6
4x = 12
x = 3

x - y = 6
3 - y = 6
-y = 6 - 3
-y = 3
y = -3

check...
3x + y = 6
3(3) - 3 = 6
9 - 3 = 6
6 = 6 (correct)

x intercept is (3,0)

Answer 3

The simplest way with this pair of equations is elimination:

3x + y = 6
x - y = 6

Add the second equation to the first:

3x +x + y - y = 6 +6
4x = 12
x=3

Therefore, the x part of the solution is 3 and not 0.