Question

evaluate (8.6)²-(1.4)² using suitable identity​

Answer 1

Answer:

72

Step-by-step explanation:

Given : (8.6)

2

−(1.4)

2

Let a=8.6, b=1.4

We know, a

2

−b

2

=(a+b)(a−b)

Applying this Identity, we get

⇒ (8.6)

2

−(1.4)

2

=(8.6+1.4)(8.6−1.4)

=(10)(7.2)

=72

Answer 2

(8.6)^2=73.96

(1.4)^2=1.96

(8.6)^2-(1.4)^2 = 73.96-1.96

= 72