11
A diagonal connects a vertex to another vertex without being a side of the polygon. There are 14 vertices in a 14-gon. This leaves 13 vertices left to connect to (since we cannot connect the vertex to itself). However, two of these vertices will form the sides of the 14-gon. This leaves us with 11 possible diagonals we can draw.
Answer:
Substitution property of equality
Step-by-step explanation:
Given
and 
Then
Required
State the property
From the list of options, (d) answers the question.
This is so because:
Substitution property of equality states that
If 
then 
In other words, both can replace one another.
So if , then 2y + 1 can be substituted for x in
So:
becomes
<em>Hence, it is substitution property of equality</em>
Note that the 2nd equation can be re-written as y=8x-10.
According to the second equation, y=x^2+12x+30.
Equate these two equations to eliminate y:
8x-10 = x^2+12x+30
Group all terms together on the right side. To do this, add -8x+10 to both sides. Then 0 = x^2 +4x +40. You must now solve this quadratic equation for x, if possible. I found that this equation has NO REAL SOLUTIONS, so we must conclude that the given system of equations has NO REAL SOLUTIONS.
If you have a graphing calculator, please graph 8x-10 and x^2+12x+30 on the same screen. You will see two separate graphs that do NOT intersect. This is another way in which to see / conclude that there is NO REAL SOLUTION to this system of equations.
The ordered pair (1,5) would be the correct answer.
It's not a must so you don't really have to it depends on the question
