Question

Evaluate using suitable identitys
4.1×4.2

Answer 1

Heya !!

$4.1 \times 4.2 \\\\= (4 + 0.1)(4 + 0.2) \\\\\text{-- Using (x+a)(x+b) = x^2 + (a+b)x + (a)(b) } \\\\= 4^2 + (0.1 + 0.2)(4) + (0.1)(0.2) \\\\= 16 + (0.3 \times 4) + 0.02 \\\\= 16 + 1.2 + 0.02 \\\\\boxed{= 17.22} \: \: \: \mathbb{ANSWER}$

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Answer 2

Heya !!

1.2 + 0.02 = 17.22
4.1×4.2
=(4+0.1)(4+0.2)
– Using (x+a)(x+b)=x 2
+(a+b)x+(a)(b)=4 2
+(0.1+0.2)(4)+(0.1)(0.2)
=16+(0.3×4)+0.02
=16+1.2+0.02
=17.22
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ANSWER
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Hope it helps !!