CBSE - Linear Equations

1 Linear Equations 

If the system of equations

                        2x + 3y = 7

                        2ax + (a + b)y = 28

has infinitely many solutions, then ________.

1)  a = 2b 
2) b = 2a 
3) a + 2b = 0 
4) 2a + b = 0

2 Linear Equations 

The value of k for which the system of equations kx - y = 2, 6x - 2y = 3 has a unique solution, is_______.

1)  = 3 
2) ≠ 3 
3) ≠ 0 
4) = 0

3 Linear Equations 

In the equations 3x + 2y = 13xy  and 4x - 5y = 2xy, the value of x and y satisfy that the equations are

1)  ( 2, 3 )
2)  ( 3, 2 ) 
3)  ( 1/2, 1/3 ) 
4)  ( 1/3, 1/2 )

4 Linear Equations 

The system of equation  x +2y =6 , 3x + 6y = 18

1) Is inconsistent  
2) Has an infinite number of solution  
3) Has a unique solution
4) None of these  

5 Linear Equations 

If  x-y = 3 and x + y ≥ 9 the least value of  x is:  

1) 6  
2) 3 
3) 2 
4) 1

6 Linear Equations 

If the system of equation  3x+ y = 1, (2k—1)x + (k - 1)y = (2k + 1) , has no solution, then the value of k is: 

1) 2 
2) 3 
3) -2 
4) 1

7 Linear Equations 

Five years ago the sum of ages of the father and the son was 40 years. In present it's ratio is 4:1, then the present age of father is………..   

1) 30 yr  
2) 40 yr 
3) 45 yr 
4) 42 yr

8 Linear Equations 

If  x + y= 7 and 3x — 2y = 11. Then the value of x will be:  

1) 5 
2) 6 
3) 7
4) 8

9 Linear Equations 

The equations representing the given graph is _____.

1)  7x + 2y = 11; y - 2x = 3 
2) 2x + 7y = 11; 5x + (35y/2) = 25 
3) 3x - 7y = 10; 8y - 6x = 4 
4) 3x - 4y = 1; 8y - 6x = 4

10 Linear Equations 

In a two digit number, the number of ten’s place is double of the number of unit’s place. If we exchange the numbers mutually then the number decrease b 18, then the number is:- 

1) 24 
2) 36 
3) 39
4) 42