Question

2x+y=1 9x + 3y = -3 The x-coordinate of the point of intersection is

Answer 1

Answer:

Step-by-step explanation:

Hello there!

If we have two equations, two lines and they intersect the key here is to find the value for x, then for y. By doing this we'll find the cartesian point for their common point. The point of intersection.

So Let us set the System of Linear equations. Solving it using the Addition Method.

$\left \{{{2x+y=1}\atop {9x+3y=-3}}\right. \\ \left \{{{2x+y=1}*(-3)\atop {9x+3y=-3}}\right. \\\left \{{{-6x-3y=-3}\atop {9x+3y=-3}}\right. \\\\ 3x :3=-6 :3\\ x=-2\\ \\2(-2)+y=1\\ y=5$

So the point of intersection is (-2,5) and x-coordinate is x=-2

Answer 2

Hello : 
2x+y=1 ....(1)
9x + 3y = -3....(2)
by (1) : y = -2x+1...(*)
by (2) : 3(3x+y) = - 3
3x+y = -1
y = -3x -1 ....(**)
by (*) (**) :
-2x+1 = -3x -1
- 2x +3x = -1 -1 
x =-2  is The x-coordinate of the point of intersection