NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 7: Algebra - True or False Questions

Question 48

Why the statement is false:

Step 1: Understand the words.

• A variable is a letter that can take different values. For example: ( k ).
• A constant is a fixed number. For example: ( 7 ).

Step 2: Look at the equation.

( 7k - 7 = 7 )

• ( k ) is the letter (it can change).
• ( 7 ) is a number (it does not change).

Step 3: Identify the variable.

The variable is the symbol that can take many values: ( k ).

Step 4: Check with small examples (just to see what a variable means).

• If ( k = 1 ): ( 7 imes 1 - 7 = 0 ).
• If ( k = 2 ): ( 7 imes 2 - 7 = 7 ).

See how ( k ) can change? That’s why ( k ) is the variable.

Step 5: Final point.

( 7 ) stays the same in every case. So ( 7 ) is a constant, not a variable.

Conclusion: The statement is false because the variable is ( k ), not ( 7 ).