When x is equal to - 1, the value of the third power of the polynomial ax + bx-3 is 2; when x = 1, what is the value of the polynomial?

When x is equal to - 1, the value of the third power of the polynomial ax + bx-3 is 2; when x = 1, what is the value of the polynomial?

-When a-b-3 = 2, x = 1, the polynomial = a + B-3, a + B = - 5 from the front, so the polynomial = - 8