ML AGGARWAL CLASS 7 Chapter 8 Algebraic Expressions Exercise 8.4

 Exercise 8.4

Question 1

i) $2 n+1$

Number of shapes

1

2

3

No of Line segments

3

5

7

n shape of letter are formed then algebraic equation is 2n + 1

ii) Number of shapes

       1

       2

       3

No, of line segments 

      5

      8

     11

Algebraic equation is 3n + 2

Question 2

i) Number of shapes

       1

       2

       3

   $\vdots$

No, of line segments

     4

     7

    10

   $\vdots$

Algebraic expression is 3nm

ii) Number of shapes 

     1

     2

     3

No. of line segments

    6

    11

     16

Algebraic expression is 5n + 1

iii) Number of shapes

         1

         2

         3

No. of line segments 

         7

         12

          17

Algebraic expression is 5n+ 2

Question 3

i) $2 n+1$

$n=5 \quad 2(5)+1=11$

$n=10 \quad 2(10)+1=21$

$n=100 \quad 2(100)+1=201$

ii) $3 n+1$

$n=5 \quad 3(5)+1=16$

$n=10 \quad 3(10)+1=31$

$n=100 \quad 3(100)+1=301$

iii) $3 n+2$

$n=5 \quad 3(5)+2=17$

$n=10 \quad 3(10)+2=32$

$n=100 \quad 3(100)+2=302$

iv) $n=5(5)+1=26$

$n=10 \quad 5(10)+1=51$

$n=100 \quad 5(100)+1=501$

v) $5 n+2$

$n=5 \quad 5(5)+2=27$

$n=10 \quad 5(10)+2=52$

$n=100 \quad 5(100)+2=502$

vi) $4 n+3$

$n=5 \quad 4(5)+3=23$

$n=10 \quad 4(10)+3=43$

$n=100 \quad 4(100)+3=403$