Ayuda plis es urgente?

- 4x² - 3x + x³ - (5x² + 6x) - 4x² - 3x + x³ - 5x² - 6x - 9x² - 9x + x³ - y³ + 5y - 1 - ( - 7y² + 8y) - y³ + 5y - 1 + 7y² - 8y - y³ + 7y² - 3y - 1

3 / 4rs + 1 / 4r²s + 5 / 4r³s - (1 / 2r³s - 1 / 7r²s)

3 / 4rs + 1 / 4r²s + 5 / 4r³s - 1 / 2r³s + 1 / 7r²s

3 / 4rs + 11 / 28r²s + 6 / 8r³s.