Start with

Simplify the left hand side by summing like terms (the one involving z):

Subtract 5z from both sides:

Subtract 7 from both sides

Divide both sides by 11:

Answer:
-48
Step-by-step explanation:
21 is 42% of 50. To do that, you divide 21 by 50, you get .42. You then multiply .42 by 100 to get your answer.
44x is the way the points are calculated. In order to find out the amount of questions there needs to be a constant, 10 which represents the number of wrong questions, and a variable, x which represents the number of correct questions. You have to know that if wrong questions were counted, he would have 440 points just for the 10 wrong questions. Next you have to add the amount of correct questions and their corresponding points. The numbers that you get should be put together with the wrong questions. The points for the wrong questions don't count but the questions do. When you find the number, (I don't know what it is so I will use x but you will have to find out what it is) you will add x, the number of correct questions to the 10 incorrect questions and then you will have 10+x for the questions. You will need to use 44x to find out the number of points and once you have done that, you use this equation to average the points over the total questions: 44x/10+x
<span>In order to find the area of a rectangle, the width must be multiplied by the length. Since we know the length is 7 yards and the width is 4 yards, we can simply multiply these two values together. 4yd x 7yd= 28yds^2.</span>