Exercise 12.1

Q1: Using arithmetic operations, constants and variables find the algebraic expressions of the cases given below:

{i) Numbers a and b both squared and added.

(ii) Number 5 added to three times the product of s and t.

(iii) One-fourth of the product of numbers m and n.

(iv) One-half of the sum of numbers a and b.

(v) Product of numbers e and f subtracted from 10.

(vi) Subtraction of v from u.

(vii) Sum of numbers s and t subtracted from their product

(viii) The number x multiplied by itself.

Sol:

(i) a2 + b2

(ii) 3st + 5

( ... ) mn 1114

(iv) a �b

(V) 10 -ef

(vi) u-v

(vii) st - (s + t)

(viii) x2

Q2:

(a) Figure out the terms and their factors in the expression given below and show them by the help of tree diagram

(i)a-3

(ii) 1 +a+ a2

(iii) y-y3

(iv)5ab2 + 7x2y

(v) -xy + 2y2 - 3x2

{b) Figure out the terms and factors in the expressions below:

(i) -4a + 5

(ii) -4a+ 5b

(iii) 5a + 3a2

(iv) ab+ 2a2b2

NCERT SOLUTIONS CLASS-VII MATHS

CHAPTER-12 ALGEBRAIC EXPRESSIONS