Expression :  $$ax^{3} + bx^{2 }+ cx + d$$ When it intersects x-axis at x = 1, => Point = (1,0) => $$a(1)^3 + b(1)^2 + c(1) + d = 0$$ => $$a + b + c + d = 0$$ --------Eqn(I) Similarly at (-1,0) => $$a(-1)^3 + b(-1)^2 + c(-1) + d = 0$$ => $$-a + b -c + d = 0$$ => $$(a + c) = (b + d)$$ Substituting it in eqn(I), we get :  => $$2 (b + d) = 0$$ => $$b + d = 0$$ ---------Eqn(II) When it intersects y-axis at  = 2, => Point = (0,2) => $$a(0)^3 + b(0)^2 + c(0) + d = 2$$ => $$d = 2$$ Substituting it in Eqn(II), => $$b = -2$$