Réponse:
Pour ces expressions il faut utiliser les identifier remarquables
rappel des identités remarquables:
[tex]{a}^{2} + 2ab + {b}^{2} = ( {a + b})^{2} [/tex]
[tex] {a}^{2} - 2ab + {b}^{2} = ( {a - b})^{2} [/tex]
[tex] {a}^{2} - {b}^{2} = (a + b)(a - b)[/tex]
pour tes expressions :
[tex]d = {x}^{2} - 2x + 1 = {x}^{2} - 2 \times x \times 1 + {1}^{2} = {(x - 1)}^{2} [/tex]
[tex]e = {9x}^{2} + 12x + 4 = {(3x)}^{2} + 2 \times 3x \times 2 + {2}^{2} = {(3x + 2)}^{2} [/tex]
[tex]f = 225 - {64x}^{2} = {15}^{2} - {(8x)}^{2} = (15 + 8x)(15 - 8x)[/tex]
[tex]g = {9x}^{2} - 30x + 25 = {(3x)}^{2} - 2 \times 3x \times 5 + {5}^{2} = {(3x - 5)}^{2} [/tex]
[tex]h = {49t}^{2} - 100 = {(7t)}^{2} - {10}^{2} = (7t + 10)(7t - 10)[/tex]
[tex]i = {4a}^{2} + 8a + 4 = {(2a)}^{2} + 2 \times 2a \times 2 + {2}^{2} = {(2a + 2)}^{2} [/tex]
