Ответ:

а). = 810 000

б). = - 9

Объяснение:

[tex] {(719 - 181)}^{2} + 4 \times 719 \times 181 = {719}^{2} - 2 \times719 \times 181 + {181}^{2} + 4 \times 719 \times 181 = {719}^{2} + 2 \times 719 \times 181 + {181}^{2} = {(719 + 181)}^{2} = {900}^{2} = 810000[/tex]

[tex]5278 \times 5272 - {5275}^{2} = (5275 + 3) \times (5275 - 3) - {5275}^{2} = {5275}^{2} - {3}^{2} - {5275}^{2} = - {3}^{2} = - 9[/tex]