Don’t open the link give you a virus
The first step for solving this problem is to multiply both sides of the bottom equation by -3.

Add the two equations together.
6x - 9y - 6x + 9y = 16 - 21
Eliminate the opposites.
-9y + 9y = 16 - 21
Remember that the sum of two opposites equals 0,, so the equation becomes the following:
0 = 16 - 21
Calculate the difference on the right side of the equation.
0 = -5
This means that the statement

is false for any value of x and y. That means that the answer to your question is (x,y) ∈ ∅,, or no solution.
Let me know if you have any further questions.
:)
To answer this question we will have to understand the nature of
.
can be rewritten as:
. Now,
is an irrational number and thus any of the four operations of addition, multiplication, subtraction or division placed anywhere between any of these terms will always result in an irrational number.
The only way irrational numbers can be made rational is by dividing or multiplying the given irrational number by the same irrational number.
C is not continuous.
Continuous functions have connected graphs; this indicates that every possible value of x has a value of y associated with it. In this case, that says that every possible radius measurement has a number of tennis balls associated with it. The problem with this is that we cannot have a fractional part of a tennis ball, so it is not continuous.