Answer:

Step-by-step explanation:
For ellipses, the length of the major axis is represents as:
Major axis = 
where
is called the semi-major axis.
In this case since the major axis is equal to 10 units:

solving for the semi-major axis
:

and also the minor axis of an ellipse is represented as:
Minor axis = 
where
is called the semi-minor axis.
Since the minor axis has a length of 8 units:

solving for b:

Now we can use the equation for an ellipse centered at the origin (0,0):

and substituting the values for
and
:

and finall we simplify the expression to get the equation of the ellipse:

Answer:
yes
Step-by-step explanation:
I think sorry if I am wrong
Brainly is good and educational for me.
Answer:
x=21.
Step-by-step explanation:
First you distribute 3 to the parenthesis. You should get 3x-21=42 at this point. Then you add 21 to 42 to get 63. Here you should be at 3x=63. Divide 63 by 3 to get x=3
Each trianglar side has an area: (1/2)*8*9=36
the base is a square with an area of 8*8=64
so the total surface area is 36+36+36+36+64=208