# CBSE Class 7 Mathematics/ Algebraic Expressions- Chapter 12

**CBSE Class 7 Mathematics/Algebraic Expressions is about some model questions that you can expect for yearly examination. Here you can find out practice problems for class 7 Mathematics. **

**CBSE Class 7 Mathematics /Algebraic Expressions – Chapter 12Important Questions for Yearly Examination**

**Answer the following:**

**What are the coefficients of x in the following expressions?**

a) 5x – 2y

b) 8 – x + y

c) 3y – 4xy

Solution:

a) Coefficient of x is 5

b) Coefficient of x is -1

c) Coefficient of x is -4y**Which of the following pairs of terms are of like terms and which are of unlike terms?**

a) 3x, 8y

b) -3ba, 5ab

c) 5xy, 5x

Solution:

a) Since the variables in the terms are different, 3x and 8y are unlike terms.

b) Since the terms have the same algebraic factors, -3ba and 5ab are like terms.

c) Since the variables in the terms are different, 5xy and 5x are unlike terms**Get the algebraic expressions in the following cases using variables, constants and arithmetic operations:**

a) Number 3 added to twice the product of numbers a and b

b) Product of numbers x and y subtracted from 12

c) One third of the sum of numbers x and y

Solution:

a) 3 + 2ab

b) 12 – xy

c) 1/3 (x + y)**Add**

a) 7m – 5n, 3n – 4m + 2, 6m + 2n + 1

b) a + b – 3, b – a + 3, a – b + 3

Solution:

a) 7m – 5n + 3n – 4m + 2 + 6m + 2n + 1 = (7m – 4m + 6m) + (-5n + 3n + 2n) + 2 + 1

= 9m +3

b) a + b – 3 + b – a + 3 + a – b + 3 = (a – a + a) + (b + b – b) + (-3 + 3 + 3)

= a + b + 3**What should be subtracted from 3xy + 6x – 8y +9 to get 1?**

Solution:

To get 1, we need to subtract 3xy + 6x – 8y + 8 from 3xy + 6x – 8y + 9