Q4 of 157 Page 22

Find out the following squares by using the identities:
(0.4a – 0.5b)²

Given (0.4a – 0.5b)²

We know that

(a– b)² = a² + b² – 2a×b

⇒ (0.4a – 0.5b)² = ((0.4a)² + (0.5b)² – 2×0.4a×0.5b)

⇒ (0.4a – 0.5b)² = 0.16a² + 0.25b² – 0.4ab

Find out the following squares by using the identities:

(7x + 3y)²

Find out the following squares by using the identities:

(10m – 9n)²

Find out the following squares by using the identities:

Questions · 157

1. Algebra

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Find out the following squares by using the identities:(0.4a – 0.5b)2