To find the equation of a line perpendicular to the given line, we need to first find the slope of the given line, using the slope formula:

Because we need to find a line perpendicular to the given line, we need to use the ** opposite reciprocal** of this slope, along with the point that is given.

Using the point *(0,0) *and the slope 5/4, we apply the formula *y=mx + b* and we get the equation for the new line: .