Answer:
27 sana makatulong hahahahah
I got (-6.28, -0.76).
Step 1.) Write out the problems
-2x=8-6y
-15x=21-6y
Step 2.) Pick a problem and solve for X
-2x=8-6y = x=-4-3y
Step 3.) Plug in the x
(-15)(-4-3y)= 21-6y
60 + 45y= 21-6y
Step 4.) Solve for y
y=-0.76
Step 5.) Plug in the y value into one of the equations
-2x= 8- 6(-0.76)
-2x= 8 + 4.56
x= -6.28
Step 6.) Check your answers
-2(-6.28)=8-6(-0.76)
12.56=12.56
Step 7.) Write it out
(-6.28,-0.76)
Surface area of cone is a sum of surface of its base and surface of its mantle.
Surface of its base is a circle which surface we will calculate like this:
Sb = pi*r^2 where r is d/2
Sb = 201m^2
Surface of mantle we calculate by:
Sm = pi*l*r where l is length of side of cone.
l =

= 25.3
Sm = 635.8m^2
Total suface is:
Sb + Sm = 836.8m^2
Between 2 and 3, after the 2 1/4 point, but before the halfway point.
The volume of a sphere is defined as:
V=(4*pi*r^3)/3
then, if we double the radius of the sphere (r=2r):
V=(4*pi*(2r)^3)/3
V=(4*pi*(2^3*r^3))/3
V=(4*pi*r^3)/3*8
Then, the answer is that if you double the radius of the sphere, its volume is increased 8 times.