M L Aggarwal Solutions for Chapter: Pair of Linear Equations in Two Variables, Exercise 4: Exercise 3.4

Solve the following pairs of linear equations by the elimination method:

$$\begin{gathered} px+qy=p-q \\ qx-py=p+q \end{gathered}$$

Solve the following pair of linear equations by the elimination method:

$$\begin{gathered} \frac{x}{a}-\frac{y}{b}=0 \\ ax+by=a^2+b^2 \end{gathered}$$

Solve the following pairs of linear equations by the elimination method:

$$\begin{gathered} \frac{x}{a}+\frac{y}{b}=2 \\ ax-by=a^2-b^2 \end{gathered}$$

Solve the following pairs of linear equations by the elimination method:

$$\begin{gathered} \frac{ax}{b}-\frac{by}{a}=a+b \\ ax-by=2ab \end{gathered}$$

Solve the following pairs of linear equations by the elimination method:

$$\begin{gathered} \frac{a^2}{x}-\frac{b^2}{y}=0 \\ \frac{a^{2}b}{x}+\frac{b^{2}a}{y}=a+b,x\ne 0,y\ne 0 \end{gathered}$$

$2$ tables and $3$ chairs together cost $₹2000$ and $2$ chairs and $3$ tables together cost $₹2500$. Find the cost of $1$ chair and $3$ tables together.

A man earns $₹600$ per month more than his wife. One-tenth of man's salary and one-sixth of wife's salary amount to $₹1500$, which is saved every month. Find their salaries?

The sum of digits of a two-digit number is $8$ and the difference between the number and that formed by reversing the digits is $18.$ Find the number?