Please answer all the step wise step factorise
1. a^2 - b^2 - 4a +4

2. x^2 -xy - 3x +2 +2y

3. 4x^2 - 4a^2 - 4a - 1

4. x^2 + 3x + 2 + ax + 2a

5. 7 ( x - 1/x )^2 + 15 ( x - 1/x ) + 2

6. 64 - 144x + 108x^2 - 27x^3

7. ab^2 - b ( a-c ) - c

8. p^2 - a ^2 - 2pr + r^2

answer: just subtact the units and then add the non negative : happy to

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

if you was gonna solve for a, a is a   < -12