First, the slope of perpendicular line have negative reciprocal coefficients. In this case the coefficient is 2, The reciprocal of 2 is 1/2 and the negative of 1/2 is -1/2. So x will have a coefficient of -1/2.
Second, find the equation with a slope of -1/2 that passes through (-2,3). There are a few ways to do this. I like to plug the given x value into the expression -1/2x, so -1/2(-2) which equals positive 1 and for the line to pass through the point (-2,3) you need to add 2. So: y=-1/2x+2
The correct answer is m = 2/1 because they first point it reaches is (1,2) and so you insert those numbers (x,y) into the rise and run equation (y/x) and get the answer 2/1.