Question

化简(1) 5xy^2+2x^2y-3xy^2-x^2y ;(2)2(2a^2+9b)+3(-5a^2-4b)

Answer 1

(1) 5xy^2+2x^2y-3xy^2-x^2y

= xy^2+x^2y

(2)2(2a^2+9b)+3(-5a^2-4b)

= 4a^2+18b -15a^2-12b

= -11a^2+6