1) (х+1)*(х-1)-(х+5)*(х-5)+(х+1)*(х-5) = x² -1 - (x² - 25) + x² - 5x + x - 5 = x² - 1 - x² + 25 + x² - 5x + x - 5 = 19 + x² - 4x = x² - 4x + 19
2) 81а⁸-(3а²-b³)*(9a⁴+b⁶)*(3а²+b³) = 81a⁸ - (9a⁴ - b⁶) * (9a⁴ + b⁶) = 81a⁸ - (81a⁸ - b¹²) = 81a⁸ - 81a⁸ + b¹² = b¹²
1) (х+1)*(х-1)-(х+5)*(х-5)+(х+1)*(х-5) = x² -1 - (x² - 25) + x² - 5x + x - 5 = x² - 1 - x² + 25 + x² - 5x + x - 5 = 19 + x² - 4x = x² - 4x + 19
2) 81а⁸-(3а²-b³)*(9a⁴+b⁶)*(3а²+b³) = 81a⁸ - (9a⁴ - b⁶) * (9a⁴ + b⁶) = 81a⁸ - (81a⁸ - b¹²) = 81a⁸ - 81a⁸ + b¹² = b¹²