Answer:
6. The number is 
7. The two numbers are
and 
Step-by-step explanation:
Question six can be re-worded to create the following expression:

Solve for x to find the number:

Question seven can be solved by first listing the constraints (assuming x is smaller than y):
- x and y are less than 20


To get the numbers, we can create a system of linear equations. First, solve for
in each expression:


Solve for
:

Solve for
:

The height of the tree is 42.
Answer:
262 and 263 are consecutive natural numbers whose sum is 525.
Step-by-step explanation:
Natural number are a subset of real numbers consisting in positive integers (i.e. 1, 2, 3, 525) and two natural numbers are consecutive when distance between each other is equal to 1. (
,
) We can interpret the statement mathematically by means of the following expression:



Where
,
,
.
This system is reduced to a single equation and solved afterwards:




Now we evaluate
and
to obtain the natural numbers:


262 and 263 are consecutive natural numbers whose sum is 525.