Answer:


Step-by-step explanation:
∠1 and ∠2 are vertical angles.
∠1 = ∠2
<u>Part A:</u>
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Create an equation and solve for x.
20x + 21 = 30x - 29
Add 29 and -20x on both sides.
20x + 21 + 29 - 20x = 30x - 29 + 29 - 20x
Simplify the equation.
50 = 10x
Divide both sides by 10.
= 
Simplify the equation.
5 = x
Switch sides.
x = 5
<u>Part B:</u>
<u></u>
Let x = 5
20(5) + 21
Distribute.
100 + 21
Add.
= 121
Since both angles are vertical angles, they are equal.
∠1 = 121°
∠2 = 121°
Given:
The different relations in the options.
To find:
The relation which represents a function.
Solution:
A relation is called a function if there exist a unique output (y-value) for each input (x-value).
In option A, there exist two outputs y=7 and y=1 for a single input x=-1. So, this is not a function.
In option B, there exist two outputs y=-5 and y=2 for a single input x=-1. So, this is not a function.
In option C, there exist two outputs y=2 and y=4 for a single input x=3. So, this is not a function.
In option D, there exist only one value of y for each x. So, this is a function.
Therefore, the correct option is D.
Easy Peasy Lemon Squeezy.
it's difficult because you are looking too hard. think simply. why does it tell you that angle is 40°?
Because if you follow the arrow back to where it starts you will see that exact same angle.
so now you know 1 (not m° or n°) angle inside the triangle is 40° and a complete triangle is 180°.
you also know a straight line has 180° on each side. and the line going from m° to n° splits that in half. meaning there is 90° to the right of it and 90° to the left of it. which means n° must equal 90°.
now you know you have 1 angle inside the triangle with 40° and n°=90° now you just need to find how much m° is.
add 40°+90° then Subtract from 180° to get m°.
180°-130°=50°
m°=50°