Question

помогите с алгеброй пж​

Answer 1

Ответ:

$1)\ \ 9y^5-5y^5+2y^5-y^5=y^5\cdot (9-5+2-1)=5y^5\\\\2)\ \ 5a+3n-9a-10n=-4a-7n\\\\x^2+7x+11-x^2-9x^2+4x-17=-8x^2+11x-6\\\\3)\ \ 7a^2+2a-7+(6a^2-5)=13a^2+2a-12\\\\4)\ \ 9m^2-7-(9m^2-3m+2)=9m^2-7-9m^2+3m-2=3m-9\\\\5)\ \ (2a+5b)+(8a-11b)+(9b-5a)=(2a+8a-5a)+(5b-11b+9b)=\\\\{}\ \ \ \ =5a+3b$