Answer:
Explanation:
The formula governing this situation is
m1 * m2 = - 1
Method One
So let m1 = 7/4
(7/4)*m2 = - 1 Multiply by 4
7*m2 = -1*4 Divide by 7
m2 = -4/7
Method Two
Most people teaching this try to get you to use reciprocals. If you know how to do that then the answer is much simpler.
7/4 m2 = -1 Multiply by 4/7
4/7 * 7/4*m2 = - 1 * 4/7
m2 = -4/7
However if you are not comfortable with reciprocals, then then the thing to do is to handle them the way I showed you in the first method.