Use the Eliminaction method 5x+2y=3 -5x-2y=2

Alana has 12.5 cups of flour with which she is baking four loaves of raisin bread and one large pretzel. the pretzel requires 2.5 cups of flour to make. how much flour is in each loaf of raisin bread? explain the steps to follow to get the answer.

Hi, can anyone show me how to do this problem? 100 points for this. in advance

What is the greatest number of parts of a circle that can be formed by cutting the circle with 7 straight cuts? (note: the parts do not have to be equal in size)