(5xy^2-3x^3+2x^2y)(2x^2-xy-4y^2)=10x^3y^2-5x^2y^3-20xy^4-6x^5+3x^4y+12x^3y^2+4x^4y-2x^3y^2-8x^2y^3=20x^3y^2-13x^2y^3-20xy^4-6x^5+7x^4y
Решение
2.
a) (a - 3)/4a² + 3/2a = (a - 3 + 6a)/(4a²) = (7a - 3)/(4a²)
б) (x³ - 1)/9x³ - (x² - 4)/(12x²) - 2 =
= (4x³ - 4 - 3x³ + 12x - 72x³)/(36x³) = (- 71x³ + 12x - 4)/(36x³)
(a-2a+1)*(ab/(a-b)) = (1-a)*ab / (b-a)