The answer is C. 20. Hope this helps!
-7x-5y=-47x+9y=-4
combine like terms to cross out the 7x
solve for y, to get -2
plug it back in to one of the equations and x is 2
y=-2
x=2
There is no image posted. However, I will tell you how to solve for the area of a drum head.
Drum head is a circle shape. We will use the formula of finding the area of a circle to solve for the area of a drum head.
Area of a circle = π r²
π is pi. It is equivalent to 3.14. Though there are still a lot of numbers after 4. To ensure uniformity, π is 3.14
r is radius. It is the line from the center of the circle to the edge of a circle.
if the diameter of a circle is given, simply divide the diameter by 2 to get the radius.
Diameter is the line that starts from one end of the circle to the other passing through the midpoint of the circle.
Example:
The drum head has a diameter of 10. What is the area.
diameter is given, so we need to get the radius: 10 ÷ 2 = 5
Area = π r²
= 3.14 * 5²
= 3.14 * 25
Area = 78.50 square unit
Area is always in a square unit.
Answer:
It's not much harder.
Calculus just requires that you put in a lot of work doing practice problems, which is something a lot of people aren't willing to do. And, it just involves a lot of memorization of formulas.
