All that matters once you have y = -2x is the y-intercept.
Examples:
y = -2x +3
y = -2x - 8
y = -2x + 4
You can change the y-intercept to whatever numbers you want.
One extra hint: All the lines with the slope of -2x will be parallel on a graph, no matter what the y-intercept is.
They are parallel.
Neither perpendicular nor parallel
x = 1 and y = 2
If X equals 2, then y = 5
y = 4x-8 and y = 2x+10 4x-8 = 2x+10 4x-2x = 10+8 2x = 18 x = 9 Substitute the value of x into the original equations to find the value of y: Therefore: x = 9 and y = 28
They are parallel.
Neither perpendicular nor parallel
There is no solution for those equations because the lines are parallel so, they never touch.
x = 1 and y = 2
x = y = 3
If X equals 2, then y = 5
None. When these two equations are graphed, the two lines are parallel. Since they never intersect, there is no point that satisfies both equations.
y = 4x-8 and y = 2x+10 4x-8 = 2x+10 4x-2x = 10+8 2x = 18 x = 9 Substitute the value of x into the original equations to find the value of y: Therefore: x = 9 and y = 28
y = 4, x = 6
3x-y = 9 2x+y = 6 Add both equations together: 5x = 15 x = 3 and y = 0
eqn 1 Y = 2X + 6 eqn 2 2X - Y = 2 Rearrange eqn2 to isolate Y eqn2 Y = 2X - 2 so 2X + 6 = 2X - 2 subtracting 2X from both sides we get 6 = -2 As this is impossible this set of equations can not be solved.
These are equations of two straight lines. Provided the equations are not of the same or parallel lines, there can be only one ordered pair. So the answer is - (not are) : (-1, 3).