Question

Answer pls. It will be very helpful.​

Answer 1

Answer:

5. (a-3)²-2(a-3)(a+3)+(a+3)².

(a-3)².

By using Formula (a-b)²=a²-2ab+b² where a=a & b=3.

(a-3)²=(a)²-2(a)(3)+(3)².

=a²-6a+9.

(a-3)(a+3).

By using formula (a-b)(a+b)=a²-b² where a=a & b=3.

(a-3)(a+3)=(a)²-(3)².

=a²-9.

(a+3)².

By using formula (a+b)²=a²+2ab+b² where a=a & b=3.

(a+3)²=(a)²+2(a)(3)+(3)².

=a²+6a+9.

(a-3)²-2(a-3)(a+3)+(a+3)²=(a²-6a+9)-2(a²-9)+(a²+6a+9). (Because (a-3)²=a²-6a+9, (a-3)(a+3)=a²-9 & (a+3)²=a²+6a+9).

=a²-6a+9-2a²+18+a²+6a+9. (Because -×-=+).

=2a²+18-2a²+18. (Because -×+=- so, -6a+6a will cancel i.e., it will be zero(0)).

=36. (Because +×-=- so, 2a²-2a² will cancel i.e., it will be zero(0)).

Sorry I didn't understand 6th question.

I think this is your answer.