Identities- STD 8

Self Evaluation/Assessment Questions

Question : 1 : (1 Mark )

Fill the blank box

(+)= +

Question : 2 (1 Mark )

Fill the blank box

(-)= -

Question : 3 (5 Mark )

Using the Identity

a(b+c)=ab+ac

Calculate


     


x = X( + )


= x + x


= +


=

Question : 4 (5 Mark )

Using the Identity

a(b-c)=ab-ac

Calculate


     


x = X( - )


= x - x


= -


=

Question : 5 (1 Mark )

Using the Identity

(a+b)(c+d)=ac+ad+bc+bd


Fill the blank box




(+)(+) =

Question : 6 (11 Mark )

Using the Identity

(a+b)(c+d)=ac+ad+bc+bd


Calculate


      X


= +


= +


∴ X =( + ) ( + )

= + + +


=

Question : 7 (9 Mark )

Using the Identity

(a+b)²=a²+2ab+b²

Calculate

     ²

²=( + )²


= ² + 2x x + ²


= + +


=

Question : 8 (9 Mark )

Using the Identity

(a-b)²=a²-2ab+b²

Calculate

     ²

²=( - )²


= ² - 2x x + ²


= - +


=

Question : 9 (11 Mark )

Using the Identity

     (a+b)(a-b)

Calculate

      x

= +


= -


∴ x =

( + ) ( - )

= ² - ²

= -

=

Question : 10 (4 Mark )