For this case we have the following equation:

We can rewrite the equation.
For this, we subtract 2.2 on both sides of the equation.
We have then:

Rewriting the equation on both sides we have:

This obtained equation is an equation equivalent to the initial equation.
Answer:
An equation that is equivalent is:
Answer:

Given:

Step-by-step explanation:

Identity used:

Answer:
the last one the red one or is that orange is right
Step-by-step explanation:
Let's call the missing side ? as shown in the problem.
Now set up a equation where everything adds up to 28x+11
?+8x+2+8x+2+5x+12=28x+11
?+21x+16=28x+11
?=28x-21x+11-16
?=7x-5
So 7x-5 is the missing side!
Hope it helps :D
SOLUTION
Draw the diagram
a median of a triangle is a line segment joining a vertex to the midpoint of the opposite side, thus bisecting that side.
Hence

SInce AC=30, Then

Thus, from the median properties of a triangle, AB = 15