Question

(ii) (x - 5) (x - 5) (iii) (3x + 2)(3x − 2)
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EXERCISE - 2.5
1. Use suitable identities to find the following products
(b) (x + 5) (x + 2)
(v) (1+x)(1+1
1
2
2
+
2.
X х
(iv)
2. Evaluate the following products without actual multiplication.
(i) 50x49
(1) 101 ~ 99 (ii) 999 x 999
(iv) 501x 501 (v) 30.5 x 29.5
3. Factorise the following using appropriate identities.
29,2
(i) 4y2 - 4y + 1​

Answer 1

Answer:

x^2+10x+25

Step-by-step explanation:

(x-5) (x-5)= (x-5)^2

= x^2-2×x×-5+ -5^2

=x^2+10x+25

(3x+2) (3x-2) = (3x)^2 - (2)^2

= 9x-4

(x+5) (x+2) = x^2 + (5+2)x + 5×2

= x^2 + 10x + 10

(1+x) (1+1) = (1)^2 + (x+1)x + 1×x

= 1+ x^2+1x+1x

101×99= (100-1) (100+1)

= (100)^2 - (1)^2

= 10000- 1

= 9999

999×999= (1000-1) (1000-1)

= (1000-1)^2

= (1000)^2 - 2×1000×1 + (1)^2

=1000000- 2000+1

=1000000-2001

=997999