Find the value of x that makes a true statement 24+x=24

Which math sentence can be used to determine if the triangle is a right triangle?

Amuffin recipe, which yields 12 muffins, calls for cup of milk for every 1 cups of flour. the same recipe calls for cup of coconut for every cup of chopped apple. to yield a batch of 30 muffins, how much flour will be needed in the mix?

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?