RD Sharma 2020 solution class 9 chapter 7 Linear Equations In Two Variables VSAQS

VSAQS

Page-7.33

Question 1:

Write the equation representing x-axis.

Answer 1:

The equation of line representing x axis is given by

Question 2:

Write the equation representing y-axis.

Answer 2:

The equation of line representing y axis is given by

Question 3:

Write the equation of a line passing through the point (0, 4) and parallel to x-axis.

Answer 3:

We are given the co-ordinates of the Cartesian plane at (0,4).
For the equation of the line parallel to x axis, we assume the equation as a one variable equation independent of x containing y equal to 4.
We get the equation as

Question 4:

Write the equation of a line passing through the point (3, 5)  and parallel to x-axis.

Answer 4:

We are given the co-ordinates of the Cartesian plane at (3,5).
For the equation of the line parallel to x axis, we assume the equation as a one variable equation independent of x containing y equal to 5.
We get the equation as

Question 5:

Write the equation of a line parallel to y-axis and passing through the point (−3, −7).

Answer 5:

We are given the co-ordinates of the Cartesian plane at (–3,–7).
For the equation of the line parallel to y axis, we assume the equation as a one variable equation independent of y containing x equal to –3.
We get the equation as

Question 6:

A line passes through the point (−4, 6) and is parallel to x-axis. Find its equation.

Answer 6:

We are given the co-ordinates of the Cartesian plane at (–4,6).
For the equation of the line parallel to x axis, we assume the equation as a one variable equation independent of x containing y equal to 6.
We get the equation as

Question 7:

Solve the equation 3x − 2 = 2x + 3 and represent the solution on the number line.

Answer 7:

We are given,

we get,

The representation of the solution on the number line, when given equation is treated as an equation in one variable.

Question 8:

Solve the equation 2y − 1 = y + 1 and represent it graphically on the coordinate plane.

Answer 8:

We are given,

we get,

The representation of the solution on the Cartesian plane, it is a line parallel to y axis passing through the point is shown below

Question 9:

If the point (a, 2) lies on the graph of the linear equation 2x − 3y + 8 = 0, find the value of a.

Answer 9:

We are given lies on the graph of linear equation.
So, the given co-ordinates are the solution of the equation.
Therefore, we can calculate the value of a by substituting the value of given co-ordinates in equation.
Substituting in equation, we get

Question 10:

Find the value of k for which the point (1, −2) lies on the graph of the linear equation x − 2y + k = 0.

Answer 10:

We are given lies on the graph of linear equation.
So, the given co-ordinates are the solution of the equation.
Therefore, we can calculate the value of k by substituting the value of given co-ordinates in equation.
Substituting in equation, we get