Answer:
--- Vertex
--- Axis of symmetry
Step-by-step explanation:
Given

Solving (a): The vertex
For an equation written in

The vertex is:

By comparison:
and 

So, the vertex is:

Solving (b): The axis of symmetry
For an equation written in

The axis of symmetry is:
x = h
In (a):

So:

Answer:
Step-by-step explanation:
m∠1=m∠3
m∠2=m∠4
3*(m∠1+m∠3)=m∠2+m∠4
3*(m∠1+m∠1)=m∠2+m∠2
3×2 m∠1=2 m∠2
m∠2=3 m∠1
now m∠1+m∠2=180°
m∠1+3 m ∠1=180
4 m∠1=180
m∠1=180/4=45°
m∠3=45°
m∠2=180-m∠1=180-45=135°
m∠4=135°
-3y -21 +8 = -28
-3y -13 = -28
-3y = -15
y= 5
Absolute value of a real number, is the distance between that number and 0 on a number line. Therefore the absolute value of 2 is 2 and negative 2