Answer:
Step-by-step explanation:
1/5 of earnings = 220,000
Let earning be x
1/5 of x = 220,000

We have
.
First let us factor the 2 to obtain,

We can now see clearly that the expression inside the parentheses is a difference of two squares.
We now write the 4 as 2². So that we obtain the expression,

Recall that

Hence our expression becomes,

Therefore, when factored completely,

Answer:

Step-by-step explanation:
Given:
The above triangle
Required
Solve for AB in terms of a, b and angle C
Considering right angled triangle BOC where O is the point between b-x and x
From BOC, we have that:

Make h the subject:

Also, in BOC (Using Pythagoras)

Make
the subject

Substitute
for h
becomes


Factorize

In trigonometry:

So, we have that:

Take square roots of both sides

In triangle BOA, applying Pythagoras theorem, we have that:

Open bracket

Substitute
and
in 


Open Bracket

Reorder

Factorize:

In trigonometry:

So, we have that:


Take square roots of both sides

Answer:
B :step 2 she didnt collect all the like terms and calculate
Step-by-step explanation:
first rewrite remove all ( )Parentheses
2nd collect all like terms and calculate
a^4 + 7a -16 -12^a^3 + 5a -3
a^4 + 12a - 19 - 12a^3 ( Like terms are 7a +5a and -16 +-3)
so she skipped the second step