Question

а и б пж помогите срочно

Answer 1

(-3xy+a)(3xy+a)=(a-3xy)(a+3xy)=a²-9x²y²
(-1-2a²b)(1-2a²b)=-(1+2a²b)(1-2a²b)=-(1-4a^4b²)=4a^4b²-1