Mathematics Question Bank for Class 9 focuses on “Equations of Lines Parallel to x-axis and y-axis”.
1. Line of the equation y=a (a is constant) is __________
a) Parallel to X – axis
b) Parallel to Y – axis
c) Makes an angle of 45 degree with X – axis
d) Makes an angle of 45 degree with Y – axis
Answer: a
2. Number of solutions of the equation x-4=0 are?
a) Infinite
b) Three
c) Two
d) One
Answer: d
Clarification: Since the given equation x-4=0 is only in one variable, i.e. x, it has only one solution and that is x=4 and it is independent of value of y.
3. Number of solutions of the equation x+0y-4=0 are?
a) One
b) Three
c) Infinite
d) Two
Answer: c
Clarification: Since the given equation is in two variables x and y and coefficient of y is 0, solutions of this equation are: (x, y) = (4, 0), (4, 1), (4, 2), …… (4, r) where r is any real number. You can see that solution only have to satisfy the value of x and it true for any real value of y. Thus the given equation has infinite solutions.