"Question 2 Find the areas of rectangles with the following pairs of monomials as their lengths and breadths respectively. (p, q); (10m, 5n); (20x^2, 5y^2); (4x, 3x^2); (3mn, 4np)
Class 8 Algebraic Expressions and Identities Page 143"
Answers
Algebraic expressions:
A combination of constants and variables connected by any or all of the four fundamental operations +, -,×,÷ is called an algebraic expression.
Terms:
The different parts of the expression separated by the sign+ or – are called the terms of the expression.
Monomials:
A monomial is a one term algebraic expression .
Multiplication of algebraic expression:
The product of two factors with like signs is positive and the product of two factors with unlike signs is negative.
Multiplication of monomials:
The coefficient of the product of two monomials is equal to the product of their coefficients and the variable part in the product is equal to the product of the variable in the given monomials.
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Solution:
we know that
Area of rectangle = Length x breadth
Area of i rectangle
(i) p x q = pq
Area of ii rectangle
(ii)10m x 5n = (10 x 5) x (m x n)
= 50mn
Area of iii rectangle
(iii) 20x² x 5y²= (20 x 5) x (x² x y²)
= 100x²y²
Area of iv rectangle
(iv) 4x x 3x²= (4 x 3 ) x ( x x²)
=12x³
Area of v rectangle
(v)3mn x 4np = (3x 4) x ( m x n x n x p )
=12mn²p
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Hope this will help you....
Algebraic expressions:
A combination of constants and variables connected by any or all of the four fundamental operations +, -,×,÷ is called an algebraic expression.
Terms:
The different parts of the expression separated by the sign+ or – are called the terms of the expression.
Monomials:
A monomial is a one term algebraic expression .
Multiplication of algebraic expression:
The product of two factors with like signs is positive and the product of two factors with unlike signs is negative.
Multiplication of monomials:
The coefficient of the product of two monomials is equal to the product of their coefficients and the variable part in the product is equal to the product of the variable in the given monomials.
=========================================================
Solution:
we know that
Area of rectangle = Length x breadth
Area of i rectangle
(i) p x q = pq
Area of ii rectangle
(ii)10m x 5n = (10 x 5) x (m x n)
= 50mn
Area of iii rectangle
(iii) 20x² x 5y²= (20 x 5) x (x² x y²)
= 100x²y²
Area of iv rectangle
(iv) 4x x 3x²= (4 x 3 ) x ( x x²)
=12x³
Area of v rectangle
(v)3mn x 4np = (3x 4) x ( m x n x n x p )
=12mn²p