bjr

25x² - 16 = (5x)² - 4² = (5x + 4) (5x - 4)

4x - 2 = 3 + 5x

4x - 5x = 3 + 2

x = -5

15,36 cm ² x 1,25² = 24 cm²

(x - 4) (2x + 7) - (3x + 1) (x - 4)

= (x - 4) (2x + 7 - (3x+1))

= (x-4) (-x + 6)

V cylindre = aire base x hauteur / 3

aire base = pi x r² = pi x 3² = 9 pi

volume = 9pi x 8 / 3 = 24 pi cm³ ou 75,36 cm³