Find the value of the polynomial $5x - 4x^2 + 3$ at $x = 0$.

Evaluate $105 \times 106$ without multiplying directly.

Factorise $6x^2 + 17x + 5$ by splitting the middle term,and by using the Factor Theorem.

Write $(3a + 4b + 5c)^2$ in expanded form.

Factorise: $x^{3}-2x^{2}-x+2$

Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer: $4 x^{2}-3 x+7$.