Réponse:

Salut, j'espère que ça pourra t'aider

[tex] {(9x - 8)}^{2} = {(9x)}^{2} - 2 \times 9x \times 8 + {8}^{2} = 81 {x}^{2} - 144x + 64[/tex]

[tex](7x - 5)(7x + 5) = {(7x)}^{2} - {5}^{2} = 49 {x}^{2} - 25[/tex]

[tex] {(5x + 4)}^{2} = {(5x)}^{2} + 2 \times 5x \times 4 + {4}^{2} = 25 {x}^{2} + 40x + 16[/tex]

[tex](9x + 1)(x - 9) = 9x \times x - 9x \times 9 + 1 \times x - 1 \times 9 = 9 {x}^{2} - 81x + x - 9 = 9 {x}^{2} - 80x - 9[/tex]

[tex] - {(10x - 9)}^{2} = - (( {10x)}^{2} - 2 \times 10x \times 9 + {9}^{2} ) = - ( {100x}^{2} - 180x + 81) = - 100 {x}^{2} + 180x - 81[/tex]

[tex](8x + \frac{2}{7} )(8x - \frac{2}{7} ) = {(8x)}^{2} - {( \frac{2}{7} )}^{2} = 64 {x}^{2} - \frac{4}{49} [/tex]