if the graph of the equation 3x+by=2 is perpendicular to the graph of 2x-3y=-4 determine the value of b

change the first equation to slope intercept form.

y=-3/b *x +2/b
change the second equation to the same form
y=2/3 x +4/3

because perpendicular lines have the negative reciprocal slope

-3/b= - (3/2)
b= 2