Evaluate the following products without multiplying directly : $103 \times 107$
Examine whether $x+2$ is a factor of $x^{3}+3 x^{2}+5 x+6$ and of $2 x+4$.
Factorise : $49 a^{2}+70 a b+25 b^{2}$
Which of the following expressions are polynomials in one variable and which are not ? State reasons for your answer. $y+\frac{2}{y}$
Factorise $4 x^{2}+y^{2}+z^{2}-4 x y-2 y z+4 x z$.