Answer:
x = -8/3
y = 4
Step-by-step explanation:
I assume you want to solve for x and y.
The best way to do this with the two formulas given is elimination. This means add the two equations together.
6x + 5y = 4
-6x + y = 20
The 6 x and -6x will cancel each other. By adding the like terms of the two together you will come out with
6y = 24
Now solve for y by dividing both sides by the 6.
y = 24/6 = 4
Now that we have y, you can plug it into one of the equations and solve for x.
Let's use -6x + y =20.
So plug in the 4 for y to get -6x + 4 = 20
Subtract the 4 from both sides then solve for y by dividing both sides by the -6.
-6x = 16
x = -16/6
You can reduce that down so that x = -8/3.
We know that
[area of a circle ]=pi*r²
diameter=4 in
r=4 in/2-----> 2 in
so
area=pi*2²-----> area of the circle=4*pi in²
the answer is
the area, in square inches, of the circle is <span>3.14 • 2²</span>
Answer:
you subtract the number by 3
Step-by-step explanation:
the pattern is x-3 so the pattern is subtracting the number by 3 every time
Th one on the left I wanna say x=16 and the right is x=10
The area of a polygon is given by the formula Area = ap/2 where a is the length of the apothem and p is the perimeter. The apothem is a line from the center of the polygon perpendicular to a side.
Depending on the formula you know, you can find the length of a side in 1 of 2 ways.
The first way uses a triangle. Using the radius of the polygon you can create 8 congruent triangles. The center angle will be 360 / 8 = 45 and two side lengths of 20. You can find the length of the base using the law of cosines.
c^2 = 20^2 + 20^2 - 2(20)(20)(cos 45)
c^2 = 400 + 400 - 800(cos 45)
c^2 = 800 - 800(cos 45)
c = sqrt(800 - 800(cos 45)
c = 15.31
The second way is to use this formula:
r = s / (2 sin(180 / n))
20 = s / (2 sin(180/8)
(20)(2)sin(22.5) = s
(40)sin(22.5) = s
s = 15.31
We need to calculate the perimeter. As there are 8 sides (8)(15.31) = 122.48
Now we need to calculate the apothem using
a = S / (2 tan (180 / n)
a = 15.31 / (2 tan (180 / 8))
a = 18.48
Now solve for the area
Area = ap/2
Area = (18.48)(122.48)/2
Area = 1131.72
perimeter = 122.48
area = 1131.72
