Subject Experts Solutions for Chapter: Algebraic Expressions, Exercise 2: WORKSHEET

$\frac{1}{3}{a}^2-\frac{2}{5}{b}^2=\frac{-4}{k}$, if $a=-2, b=2$, then find the value of $k$.

Evaluate $a^4-b^4$ if $a=2, b=1$.

Find the value of $4x^3-7xy+9$, if $x=1, y=2$

Total students in a school are $7a^2+5a+9$ in which number of boys are $2a^2-a+2$. If the number of girls who are enrolled is of the form $k{a}^2+ma+n$, then find the value of $\left(k+m+n\right)$.

If the sum of $-a^2+5a+7$ and $7a^2-5a+5$ is subtracted from the sum of $4a+5$ and $-5a+7$ to get the result as $k{a}^2+ma$, then find the value of $\left(k+m\right)$.

Simplify the expressions and find its value when $m=-1$ and $n=3$,
$5m^2{n}^2-3m^2+6m^2-\left(9n^2+2m^2{n}^2\right)$

The perimeter of a triangle is $(7x-15) \mathrm{cm}$. The two sides are $(x-3) \mathrm{cm}$ and $(2x+1) \mathrm{cm}$. Find the third side.

If $A=\left(x^2+2x+7\right)$ and $B=\left(x^2-1\right)$. Find $m+n$ if $A+B=m{x}^2+nx+6$.