2y + 2y = … (2x² – 8 – 9y³ + 8x³) + (8y – 6 – 5x³ – 5y³) = …

NOMOR 1.

2y + 2y = 4y

NOMOR 2.

(2x² – 8 – 9y³ + 8x³) + (8y – 6 – 5x³ – 5y³)

= 2x² – 8 – 9y³ + 8x³ + 8y – 6 – 5x³ – 5y³

= 8x³ – 5x³ + 2x² + 8y – 9y³ – 5y³ – 8 – 6

= 3x³ + 2x² + 8y – 14y³ – 14