(0,3b³)²-x² = 0.09b⁶-x²
(21d²)²-(k³)² = 441d⁴-k⁶
(1,9c^4+ 6d)(6d-1,9c^4) = (6d-1,9c^4)(6d+1,9c^4) = (6d)²-(1.9c⁴)² = 36d²-3.61c⁸
(0,3b³)²-x² = 0.09b⁶-x²
(21d²)²-(k³)² = 441d⁴-k⁶
(1,9c^4+ 6d)(6d-1,9c^4) = (6d-1,9c^4)(6d+1,9c^4) = (6d)²-(1.9c⁴)² = 36d²-3.61c⁸