Determine whether there exists a constant cc such that the line x+cy=−5x+cy=−5 has slope −6

What is best way to getting answer for my exam is

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.

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.