All exercises involve the same concept, so I'll show you how to do the first, then you can apply the exact same logic to all the others.
The first thing you need to know is that, when a certain quantity multiplies a parenthesis, you can distribute that number to every element in the parenthesis. This means that

So,
is multiplying the parenthesis involving
and
, and we distributed it:
multiplies both
and
in the final result.
Secondly, you have to know how to recognize like terms, because they are the only terms you can sum. Two terms can be summed if they have the same literal expression. So, for example, you cannot sum
, and neither
exponents count.
But you can su, for example,

or

So, take for example exercise 9:

We distribute the 1.2 through the first parenthesis:

And you can distribute the negative sign through the second parenthesis (it counts as a -1 to distribute):

So, the expression becomes

Now sum like terms:

5x10x1 electrical and electrical equipment for electrical
Answer:
<h2><u>question 1</u></h2>

use product and sum method
product = -96
sum = -20
numbers needed = ( -24 , 4)
n - 24 = 0
n + 4 = 0
hence <u>n = 24 and n = -4 </u>
<u></u>
<h2><u>Question 2 </u></h2>
<u />
<u />
in the form 
= 
make use of the formula :

replace values to make 2 equations :
1.
= 3.17
2.
= -15.2
hence <u>x = 3.17 and x = -15.2</u>
<u />
<h2><u>Question 3 </u></h2>
<u />
<u />
use product and sum method
product = 40
sum = -14
numbers needed = (-10 , -4)
x - 10 = 0
x - 4 = 0
hence<u> x = 10 and x = 4</u>
<u />
<h2><u>Question 4 </u></h2>
<u />
<u />
in the form 
this becomes 
= 
can simplify by 5
= 
use product and sum method
product = -5
sum = -4
numbers needed (-5 , 1)
b-5 = 0
b + 1 = 0
hence <u>b = 5 and b = -1</u>
There would be 868 steps. since there is 245 MORE steps in castle be than in castle a, you would have to add 623 to 245
Ok, first group x terms
f(x)=(x²+4x)-8
factor out quadratic coefient (no need but that's the step)
f(x)=1(x²+4x)-8
take 1/2 of the linear coefient and square it
4/2=2, (2)²=4
add positive and negative of it insides the parenthasees
f(x)=1(x²+4x+4-4)-8
factor perfect square
f(x)=1((x+2)²-4)-8
distribute
f(x)=1(x+2)²-4-8
f(x)=1(x+2)²-12
and, now if we wanted to find the x intercepts where f(x)=0 then
0=1(x+2)²-12
12=(x+2)²
+/-2√3=x+2
-2+/-2√3=x
x=-2+2√3 or -2-2√3
that is where the x intercept are
and completed square form is
f(x)=(x+2)²-12