If you are good at science pls answer these questions (only 4 questions)

What is the value of x when x + 7 = 21?

Barney & noblet customers can choose to purchase a membership for $25 per year members receive 10% off all store purchases 1. how much would a member pay per year if he bought $50 worth of items each year? 2. write a slope-intercept equation that expresses how much a member pays per year using x to represent his purchases per year 3. how much would a member have to spend per year to pay off his membership fee?

What is the area of this parallelogram? 434.28 cm2 263.67 cm2 527.34 cm2 217.14 cm2