Bonsoir, j’aurais besoin d’aide pour les exercices 8 et 9. Pour demain premier cours. Merci d’avance ;)

Explications étape par étape:

8) T= x² + 8x +16

= x² + 2×x×4 + 4²

= (x+4)²

U= y² +2y +1

= y² + 2×y×1 + 1²

= (y+1)²

V= x² -14x +49

= x² - 2×x×7 + 7²

= (x-7)²

W= x² -16x +64

= x² - 2×x×8 + 8²

= (x-8)²

X= 4x² - 49

= (2x)² - 7²

= (2x -7)(2x +7)

Y= 100 -9y²

= 10² - (3y)²

= (10 - 3y)(10 + 3y)

Z= (2x +1)² - 64

= (2x +1)² - 8²

= (2x +1 -8)(2x +1 +8)

= (2x -7)(2x +9)

9) 1) A= (4x -3)² - (3x +1)(4x -3)

= [(4x)² - 2×4x×3 + 3²] - [3x×4x - 3x×3 + 1×4x - 1×3]

= (16x² -24x +9) - (12x² - 9x + 4x - 3)

= (16x² -24x +9) - (12x² -5x -3)

= 16x² -24x +9 -12x² +5x +3

= 16x² -12x² -24x +5x +9 +3

= 4x² -19x +12

2) A= (4x -3)² - (3x +1)(4x -3)

= (4x -3) [(4x -3) - (3x +1)]

= (4x -3) (4x -3 -3x -1)

= (4x -3)(x -4)

3) A= (4x -3)² - (3x +1)(4x -3)

= (4×0 -3)² - (3×0 +1)(4×0 -3)

= (0-3)² - (0+1)(0-3)

= (-3)² - 1 × (-3)

= 9 +3

= 12

4) A= (4x -3)² - (3x +1)(4x -3)

= (4×4 -3)² - (3×4 +1)(4×4 -3)

= (16 -3)² - (12+1)(16-3)

= 13² - (13×13)

= 169 - 169

= 0