Answer:
Height of the pine tree = 60 in.
Step-by-step explanation:
Since, triangle formed by the tip of the tree and tip of the shadow of the tree will be similar to each other,
By the property of similarity, corresponding sides of the similar triangles will be proportional.

If d = 12 inches,

x = 
x = 60 in.
Therefore, height of the pine tree will be 60 in.
Answer:
P = 10y + 4
Step-by-step explanation:
P = 2L + 2W
P = 2(4y) + 2(y + 2)
P = 8y + 2y + 4
P = 10y + 4
Step-by-step explanation:
a) Give two pairs which are in the relation
and two pairs that are not.
As stated before, a pair
is equal mod m (written
) if
. Then:
- x=0 and y=4 is an example of a pair

- x=0 and y=1 is an example of a pair

b) Show the
is an equivalence relation.
An equivalence relation is a binary relation that is reflexive, symmetric and transitive.
By definition
is a binary relation. Observe that:
- Reflexive. We know that, for every m,
. Then, by definition,
. - Symmetry. It is clear that, given x,y and m such that
, then
. Therefore 
- Transitivity. Let x,y,z and m such that
and
. Then,
and
. Therefore:
.
In conclusion,
defines an equivalence relation.
The complex number are formed by a real part and an imaginary part.
The imaginary part is indicated with the letter i.
2i is only imaginary, so it is not complex
i - 1 is complex but is out of the triangle.
1 - i indeed is complex and is inside the triangle
2 - 3i is complex but is out of the triangle.
So, the answer is 1 - i