Give possible expressions for the length and breadth of the rectangle whose area is given by $4 a^{2}+4 a-3$
Area: $4 a^{2}+4 a-3$
Using the method of splitting the middle term, we first two numbers whose sum is +4 and produce is $4 \times(-3)=-12$
Now, $+6-2=+4$ and $(+6) \times(-2)=-12$
We split the middle term $4 a$ as $4 a=+6 a-2 a$,
So, that $4 a+4 a-3=4 a^{2}+6 a-2 a-3$
$=2 a(2 a+3)-1(2 a+3)$
$=(2 a-1)(2 a+3)$
Now, area of rectangle $=4 a^{2}+4 a-3$
Also, area of rectangle = length $\times$ breadth and $4 a^{2}+4 a-3=(2 a-1)(2 a+3)$
So, the possible expressions for the length and breadth of the rectangle are length $=(2 a-1)$ and breadth $=(2 a+3)$ or, length $=(2 a+3)$ and breadth $=(2 a-1)$
Which of the following expressions is a polynomial, state the reason ? If an expression is polynomial, state whether it is a polynomial in one variable or not
$5 x^{2}+11 x-2 \sqrt{x}$
Factorise
$x^{2}+4 y^{2}+9 z^{2}-4 x y-12 y z+6 z x$
Factorise
$8 x^{3}+125 y^{3}+343-210 x y$
Factorise the following:
$9 x^{2}+4 y^{2}+16 z^{2}+12 x y-16 y z-24 x z$
Find $p(1), p(2)$ and $p(4)$ for each of the following polynomials
$p(x)=x^{3}+9 x^{2}+23 x+15$