Algebraic Expressions - Worksheets

 CBSE Worksheet-1

CLASS -VII Mathematics (Algebraic Expressions)

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Choose correct option in questions 1 to 4.

1. Multiply 2a and 3a.
   a. 6a2
   b. 5a2
   c. a2
   d. 12a2
2. Get the algebraic expressions for subtraction of z from y.
   a. y + z
   b. y - z
   c. y × z
   d. yz$\frac{y}{z}$
3. Find the value of x + 4 for x = 2.
   a. 2
   b. 4
   c. 6
   d. 8
4. Find the product of (2x + 3y) (2x + 3y).
   a. 5x2 + 9y2 + 12xy
   b. 4x2 + 7y2 + 12xy
   c. 4x2 + 9y2 + 13xy
   d. 4x2 + 9y2 + 12xy

Fill in the blanks:

5. When terms have the same algebraic factor, they are called __________.
6. An expression which contains two unlike terms is called _______.
7. A _________ can take various values.
8. Find the product:(23xyz)(34x2y2z2)(45x3y3z3)$(\frac{2}{3}xyz)(\frac{3}{4}{x}^2{y}^2{z}^2)(\frac{4}{5}{x}^3{y}^3{z}^3)$ .
9. Simplify these expressions and find their values,if x= 3,a= - 1,b= - 2.
   a. 3x- 5a - x2 + 9b
   b. 2b - 8x + 4x2 + 4a
10. Simplify combining like terms:
    a. 3a - 2b - ab - (a - b + ab) + 3ab + b - a
    b. 5x2y - 5x2 + 3yx2 - 3y2 + x2 - y2 + 8xy2 - 3y2
11. What should be taken away from 3x2 - 4y2 + 5xy + 20 to obtain - x2 - y2 + 6xy + 20?

CBSE Worksheet-1
CLASS -VII Mathematics (Perimeter and Area)
Answer key

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1. a
2. b
3. c
4. d
   Explanation: (2x + 3y) (2x + 3y) = 2x(2x + 3y) +3y(2x + 3y)
   = 4x2 + 6xy + 6xy +9y2 = 4x2 + 9y2 + 12xy
5. like terms
6. binomial
7. variable
8. 25x6y6z6$\frac{2}{5}{x}^6{y}^6{z}^6$
9. a. -13
   Explanation: when x = 3,a= - 1,b = - 2.
   3x- 5a -x2+ 9b = 3x3 - 5 x(-1) - (3)2 + 9 (-2)= 9 + 5 -9 -18 = -13
   b. 4
   Explanation: when x = 3,a= - 1,b = - 2.
   2b - 8x+ 4x2+ 4a = 2(-2) - 8(3) + 4(3)2 + 4(-1) = -4 - 24 + 36 - 4 = 4
10. a. a + ab
    Explanation: 3a - 2b - ab - (a - b + ab) + 3ab + b - a
    = 3a - 2b - ab - a + b - ab + 3ab + b - a = a + ab
    b. 8x2y + 8xy2 - 4x2 - 7y2
    Explanation: 5x2y - 5x2 + 3yx2 - 3y2 + x2 - y2 + 8xy2 - 3y2
    = 8x2y - 4x2 - 7y2 + 8xy2
11. 4x2 - 3y2 - xy
    Explanation: 3x2 - 4y2 + 5xy + 20 - (- x2 - y2 + 6xy + 20)
    = 3x2 - 4y2 + 5xy + 20 + x2 + y2 - 6xy - 20
    = 4x2 - 3y2 -xy