Complete the equation: x^2+8x + _=(_)^2

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

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.

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?