Question

дам за это 35 баллов

Answer 1

Объяснение:

$1)~ (5x^2-6y^2)(6x^2-5y^2)=5x^2\cdot 6x^2-5x^2\cdot 5y^2-6y^2\cdot 6x^2+6y^2\cdot 5y^2=\\\\=30x^{2+2}-25x^2y^2-36x^2y^2+30y^{2+2}=30x^4-61x^2y^2+30y^4\\ \\ 2) ~(a^2+2b)(2a+b^2)=a^2\cdot 2a+a^2\cdot b^2+2b\cdot 2a+2b \cdot b^2=2a^{2+1}+a^2b^2+\\\\+4ab+2b^{1+2}=2a^3+a^2b^2+4ab+2b^3 \\ \\ 3)~(x^2+2x+1)(x+3)=x^2\cdot x+2x\cdot x+1\cdot x+x^2\cdot 3+2x\cdot3+1\cdot3=\\ \\=x^3+2x^2+x+3x^2+6x+3=x^3+5x^2+7x+3$

Answer 2

(5x^2-6y^2)(6x^2-5y^2)=5x^2×6x^2-5x^2×5y^2-6y^2-6x^2-6y^2×(-5y^2)=30x^4-25x^2y^2-36x^2y^2+30y^4=30x^4-61x^2y^2+30y^4

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

(x^2+2x+1)(x+3)= x^2×(x+3)+2x(x+3)+1(x+3)= x^3+3x^2+2x^2+6x+x+3= x^3+5x^2+7x+3