Cet exercice est un qcm svp

Bonjour,

1) On applique le théorème de Thalès.

AS/AB = ST/BC

42/125 = ST/75

ST = 42 * 75 / 125

ST = 25,2 m

2) (3x + 5)(x - 4)

= 3x² - 12x + 5x - 20

= 3x² - 7x - 20

3) Un multiple de 7.

4) 3(x + 1) + (x + 1)(x - 5)

= (x + 1)(3 + x - 5)

= (x + 1)(x - 2)

5) F(x) = x² - 4x

F(10) = 10² - 4(10)

f(10) = 100 - 40

f(10) = 60