M, or slope, is needed to define if a set of lines are parallel or not.
You could do a few (3-4)milk carton
I think the question meant if he added 3/4 of the ingredients, in which case it he needs to add two more.
Special right triangles. A special right triangle is a right triangle with some regular feature that makes calculations on the triangle easier, or for which simple formulas exist. For example, a right triangle may have angles that form a simple ratio, such as 45-45-90. This is called an "angle based" right triangle.