Answer:
1) 2 should be added with 12 only and not with 6x as 6x and 2 are not like terms.
2) When adding polynomials, You should add only like terms.
Explanation:
The steps done are:
Step 1: y-2=6x+12
Step 2: Add 2 on both sides
y-2+2=6x+12+2
Answer : y=8x+14
1) What mistake did I made?
You made a mistake in step 2,
When adding polynomials, you add only like terms. i.e
y-2+2=6x+12+2
y=6x+14
2 should be added with 12 only and not with 6x as 6x and 2 are not like terms.
2) Suggestion to avoid Such mistake in the future.
When adding polynomials, You should add only like terms.
Like terms are those that have same degree of variables i,e
2x and 3x, 2x^2 and 3x^2, 2 and 3 they all are like terms.
You can add 2x and 3x but can't add 2x and 2x^2 as they are not like terms.
So, while solving polynomials always add like terms.