Question

(m-5n)(m+5n)+(5n-1)^2

Answer 1

${m}^{2} + 5mn - 5mn - 25 {n}^{2} + 25 {n}^{2} - 10n + 1 = {m}^{2} - 10n + 1$

Answer 2

(m - 5n)(m + 5n) + (5n - 1)² = [m² - (5n)²]+ 25n² - 10n + 1 = m² - 25n² + 25n² -
- 10n + 1 = m²  - 10n + 1

Answer 3

эм, я же уже ответила