If the simple interest on $4,000 for 9 years is $3,240 , then what is the interest rate?

g

step-by-step explanation:

for this case we have by definition, if two lines are perpendicular, then the product of their slopes is -1.

then, given the following line:

so,

we are looking for m_ {2}:

then, the line is given by:

we find "b" replacing the given point:

finally, the equation is:

option c