Question

using appropriate identity find 2/3×-5/7+7/3+2/3×-2/7​

Answer 1

Answer:

(2a−7)(2a−7)=(2a−7)2

using identity (a−b)2=a2−2ab+b2

(2a−7)2=(2a)2−2×2a×7+72

(2a−7)2=4a2−28a+49

Answer 2

Answer:

$\frac{2}{3} \times \frac{ - 5}{7} + \frac{7}{3} + \frac{2}{3} \times \frac{ - 2}{7} \\ = \frac{ - 10}{21} + \frac{7}{ 3} + \frac{ - 4}{21} \\ = \frac{ - 14 + 49}{21} = \frac{35}{21}$

hope it helps you ✌️✅✅✅