Question

why here in 3rd step minus sign is not changed into positive ?​

Answer 1

Answer:

hi

because the square is only for the number 3

(a+b)(a-b) =a^2-b^2

here the square is for only the values a and b not the sign

hope it helps .pls mark as brainliest

Answer 2

Answer:

bro because any coefficient/number/variable cannot be negative

so it like this

[(a)2] - [(b)2]