Solve this system using the equal values method y=-4x -3 and y=-4x+1

Question

Having trouble solving this equation.  When I try to use the equal values method I end up with 0x

Answer 1

y=-4x -3 and y=-4x+1

 

-4x -3 = -4x+1

 

Add 4x to both sides:

-3 = +1 is not true, so no solution (implies parallel lines).

 

BTW, if a problem got to this point with equal constants then it has an infinite number of solutions (implies collinear lines).

Answer 2

Hi Brynn;

Both these equations are in the slope-intercept format of...

y=mx+b

m is the slope.

b is the y-intercept, the value of y when x=0.

The slope of both of these equations is -4.

One equation has a y-intercept of -3, coordinate is (0,-3).

The other equation has a y-intercept of 1, coordinate is (0,1).

These are parallel lines which cross the y-axis at different points.

No resolution is possible.