SCERT AP 7th Class Maths Solutions Pdf Chapter 9 Algebraic Expressions Review Exercise Questions and Answers.
AP State Syllabus 7th Class Maths Solutions 9th Lesson Algebraic Expressions Review Exercise
Question 1.
Identify constants and variables in the following terms:
0, – x, 3t, – 5, 5ab, – m, 700, – n, 2pqr, – 1, ab, 10, – 6z
Answer:
Given, 0, – x, 3t, – 5, 5ab, – m, 700, – n, 2pqr, – 1, ab, 10, – 6z
Constants = 0, – 5, 700, – 1, 10
Variables = – x, 3t, 5ab, – m, – n, 2pqr, ab, – 6z.
Question 2.
Observe the pattern the side and express the pattern in the form of an algebraic expression.
Answer:
In row = 1, 2(1) + 1 = 3
In row = 2, 2(2) + 1 = 5
In row = 3, 2(3) + 1 = 7
In row = 4, 2(4) + 1 = 9
In row = n, 2(n) + 1 = 2n + 1
Question 3.
Write the following statements as expressions
(i) x reduced by 5
Answer:
Given x reduced by 5 = x – 5
(ii) 8 more than twice of k
Answer:
Given 8 more than twice of k = 2k + 8
(iii) Half of y
Answer:
Given Half of y = \(\frac{1}{2}\) of y = \(\frac{y}{2}\)
(iv) One fourth of product of b and c
Answer:
Given One fourth of product of b and c
= \(\frac{1}{4}\) of b × c
= \(\frac{1}{4}\) × bc = \(\frac{b c}{4}\)
(v) One less than three times of p
Answer:
Given One less than three times of p
= 3 times of p – 1
= 3 ∙ p – 1
Question 4.
Write the following expressions as statements :
(i) s + 3
Answer:
Given s + 3 = 3 added to s.
(ii) 3p + 10
Answer:
Given 3p + 10
= 10 more than thrice of p.
(iii) 5c – 8
Answer:
Given 5c – 8 = 8 less than 5 times of c.
(iv) 10z
Answer:
Given 10z = 10 times of z.
(v) \(\frac{b}{9}\)
Answer:
Given \(\frac{b}{9}\) = one nineth of b.
Question 5.
Write the following situations into algebraic expressions :
(i) Cost of one pen is double the cost of pencil.
Answer:
Let the cost of pencil = ₹x
then the cost of pen = double the cost of pencil = 2 × ₹ x
∴ The cost of pen = ₹ 2x
(ii) Age of John is 10 more than age of Yusuf.
Answer:
Let the age of Yusuf = a years
then the age of John = (a + 10) years
(iii) Height of Siri is 15 cm less than height of Giri.
Answer:
Let the height of Giri = x cm
then the height of Siri = (x – 15) cm
(iv) Length of a rectangle is 2 more than three times of it’s breadth.
Answer:
Let the breadth = b units
then the length of rectangle
= 3 times b + 2
= (3 ∙ b + 2) units.