Use suitable identity to solve (1.1m−0.4)(1.1m+0.4)
Finding (1.1m−0.4)(1.1m+0.4):
Using the identity,
(a-b)(a+b)=a2-b2,
On comparing, (1.1m−0.4)(1.1m+0.4) with a-ba+b, we get,
a=1.1m,b=0.4,
∴(1.1m−0.4)(1.1m+0.4)=1.1m2-0.42=1.1m×1.1m-0.4×0.4=1.21m2-0.16
Question 1(v) Use a suitable identity to get each of the following products: (1.1m – 0.4 ) (1.1m + 0.4 )
Use a suitable identity to get each of the following products.
(i) (x + 3) (x + 3) (ii) (2y + 5) (2y + 5)
(iii) (2a − 7) (2a − 7) (iv)
(v) (1.1m − 0.4) (1.1 m + 0.4) (vi) (a2 + b2) (− a2 + b2)
(vii) (6x − 7) (6x + 7) (viii) (− a + c) (− a + c)
(ix) (x) (7a − 9b) (7a − 9b)