(a + b)(a - b) = a² - b²
32) b (3x + 7)(3x -7)
9x² - 21x + 21x - 49
9x² - 49
33) c (2/3x ) ² - 1²
4/9x² - 1
34) a = faux (x + 5)² = x² + 10x + 25
b = vrai (4 + 5x) = 16 + 40x + 25x²
c = faux signe après 4x² faux = (2x - 3)² = 4x² - 12x + 9
d = faux ( 3x - 2)² = 9x² - 12x + 4
e = vrai
35) a. (x + 1)² = x² + 2*x*1 + 1² = x² + 2x + 1
b. (2 + x)² = 2² + 2*2*x + x² = 4 + 4x + x²
c. (x + 3)² = x² + 2*x*3 + 3² = x²+ 6x + 9
d. (x + 5)² = x² + 2*x*5 + 5² = x² + 10x + 25
e) (x + 7)² = x² + 2*x*7 + 7² = x² + 14x + 49
f) (4 + x)² = 4² + 2*4*x + x² = 16 + 8x + x²
36) a . (x - 1)² = x² - 2*x *1 + 1² = x² + 2x + 1
b. (x - 4)² = x² - 2*x*4 + 4² = x² - 8x + 16
c. ( 5 - x)² = 5² - 2*5*x + x² = 25 - 10x + x²
d. ( 2 - 3x)² = 2² - 2*2*3x + (3x)² = 4 - 12x + 9x²
e. ( 1 - 3x)² = 1² - 2*1*3x + (3x)² = 1 - 6x + 9x²
f. (3 - 4x)² = 3² - 2*3*4x + (4x)² = 9 - 24x + 16x²
37) a. (x + 1)(x - 1) = x² - 1² = x² - 1
b. (x + 3)(x - 3) = x² - 3² = x² - 9
c . (5 - x)(5 + x) = 5² - x² = 25 - x²
d. (3x + 4)(3x - 4) = (3x)² - 4² = 9x² - 16
je mets 3x entre () sinon c'est que le x qui est au carré
(a + b)² = a² + 2ab + b²
(a - b)² = a² - 2ab + b²
