Evaluate using formulae - 5-7 - 5-7 - 2-3 - 2-3-5-7 - 5-7 - 2 - 5-7 - 2-3 - 2-3 - 2-3

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Expansion of (a ± b ± c)²

Evaluate usin...

Question

Evaluate (using formulae) : $\frac{5.7 \times 5.7 - 2.3 \times 2.3}{5.7 \times 5.7 + 2 \times 5.7 \times 2.3 + 2.3 \times 2.3}$

0.4

No worries! We‘ve got your back. Try BYJU‘S free classes today!

0.6

No worries! We‘ve got your back. Try BYJU‘S free classes today!

0.425

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

0.628

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C $0.425$
Using the identities
$a^{2} - b^{2} = (a + b) (a - b)$
$(a + b)^{2} = a^{2} + 2 a b + b^{2}$
$∴ \frac{5.7 \times 5.7 - 2.3 \times 2.3}{5.7 \times 5.7 + 2 \times 5.7 \times 2.3 + 2.3 \times 2.3}$ = $\frac{(5.7 + 2.3) (5.7 - 2.3)}{(5.7 + 2.3)^{2}}$
= $\frac{5.7 - 2.3}{5.7 + 2.3}$
= $\frac{3.4}{8}$ = $0.425$

Suggest Corrections

Similar questions

Q. Find the value of the series

2 + \frac{5}{| 2 - . 3} + \frac{5.7}{| 3 - . 3^{2}} + \frac{5.7.9}{| 4 - . 3^{3}} + . . .

The freezing point (in $^{\circ}$ C) of solution containing 0.1g of $K_{3} [F e (C N)_{6}]$ (mol.wt. 329) in 100g of water ( $K_{f} = 1.86 K k g m o l^{- 1}$ ) is

Q. The freezing point (in

^{\circ} C

) of a solution containing 0.1 g of

K_{3} [F e (C N)_{6}] (m o l w t = 329)

in 100 g of water

(k f = 1.86 K k g / m o l)

Q. The freezing point

(^{\circ} C)

of a solution containing 0.1 g of

K_{3} [F e (C N)_{6}]

(molecular weight 329) in 100 g of water

(K_{f} = 1.86 K k g m o l^{- 1})

Q. Evaluate:

\frac{2.3 \times 2.3 \times 2.3 - 1}{2.3 \times 2.3 + 2.3 + 1}

Join BYJU'S Learning Program

Evaluate (using formulae) : 5.7×5.7−2.3×2.35.7×5.7+2×5.7×2.3+2.3×2.3

The correct option is C 0.425Using the identitiesa2−b2=(a+b)(a−b)(a+b)2=a2+2ab+b2∴5.7×5.7−2.3×2.35.7×5.7+2×5.7×2.3+2.3×2.3 = (5.7+2.3)(5.7−2.3)(5.7+2.3)2= 5.7−2.35.7+2.3= 3.48= 0.425

Evaluate (using formulae) : $\frac{5.7 \times 5.7 - 2.3 \times 2.3}{5.7 \times 5.7 + 2 \times 5.7 \times 2.3 + 2.3 \times 2.3}$