Répondre :
E= (2x-1)(x+8)(3x+5)
calculer E pour x=-5/7
E=(2*(-5/7)-1)*(-5/7+8)*(3*(-5/7)+5)
E=(-17/7)*(51/7)*(20/7)
E=-17340/343
calculer E pour x=-5/7
E=(2*(-5/7)-1)*(-5/7+8)*(3*(-5/7)+5)
E=(-17/7)*(51/7)*(20/7)
E=-17340/343
E = ( 2 x (-5/7) - 1 ) ( -5/7 + 8 ) ( 3 x (-5/7) + 5 )
= ( -10/7 - 1 ) x 51/7 x ( -15/7 + 5 )
= -17/7 x 51/7 x 20/7
= -867/49 x 20/7
= -17 340/343
= ( -10/7 - 1 ) x 51/7 x ( -15/7 + 5 )
= -17/7 x 51/7 x 20/7
= -867/49 x 20/7
= -17 340/343