X=−4a 2 +3ab+12b 2 Y=9a 2 +ab−7b 2 Y+X=Y+X=Y, plus, X, equals

5a  

2

+4ab+5b  

2

Step-by-step explanation:

step  1. (((0-(4•(a2)))+3ab)+(12•(b2)))+(((9•(a2))+ab)-7b2)

 step 2. (((0-(4•(a2)))+3ab)+(12•(b2)))+((32a2+ab)-7b2)

step 3.(((0-(4•(a2)))+3ab)+(22•3b2))+(9a2+ab-7b2)

step 4. (((0-(4•(a2)))+3ab)+(22•3b2))+(9a2+ab-7b2)

step 5. 5.1    Factoring    5a2 + 4ab + 5b2

step-by-step explanation:

1. practice, practice & more practice

2. review errors

3. master the key concepts

do not try to memorise the processes.

4. understand your doubts.

5. create a distraction free study environment

6. create a mathematical dictionary

7. apply maths to real world problems.