Question

Упростите выражения.
а) 13a^4-28a^4+19a^4
б) 7x^2y^2x+25xyx^2y-18yx^3y

Answer 1

a)
$13a^4-28a^4+19a^4=a^4(13-28+19)=4a^4$
б)
$7x^2y^2x+25xyx^2y-18yx^3y=7x^3y^2+25x^3y^2-18x^3y^2=$$=x^3y^2(7+25-18)=14x^3y^2$