4 x 5 mũ 2 trừ x chia 2 mũ 3 91 July 8, 2019 16 32 64 128 2 + 3 + 4 + 5 + 6 2 x 2 5 2 ⋅ ( x − 9 5 ) − 3 ⋅ ( x + 1 8 ) = − 4 4
