10a2 + a - 7 + 2a -a3 -3a + 3 При а = 1/3

Question

10a2 + a - 7 + 2a -a3 -3a + 3
При а = 1/3

Answer 1

10а²+а-7+2а-а³-3а+3=10а²-а³-4=а²(10-а)-4=(1/3)²(10-1/3)-4=-81/27=-3