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.