Question

25a^2- Чь^2 - 28Ьc - Ч9c^2​

Answer 1

Answer:

$(5a + 2b - 7c)(5a - 2b + 7c)$

Explanation:

${25a}^{2} - {4b}^{2} - 28bc - {49c}^{2} \\ = {25a}^{2} - ( {4b}^{2} + 28bc + {49c}^{2} ) \\ = {25a}^{2} - ({2b + 7c})^{2} \: \: \: using \: identity \: {a}^{2} + 2ab + {b}^{2} = {(a + b)}^{2} \\ = {(5a)}^{2} - {(2b + 7c)}^{2} \\ = (5a + (2b - 7c))(5a - (2b - 7c)) \: \: \: using \: identity \: {a}^{2} - {b}^{2} = (a + b)(a - b) \\ = (5a + 2b - 7c)(5a - 2b + 7c)$

Answer 2

Answer:

This is the answer

Explanation: