Bonsoir
N°10
Sachant que a = 4, b = -5, c = 6 et d = -3
E = 3a +c/d
E = 12 + (- 6/3) = 12 -2 = 10
F = -4 (b +d) - bc
F = -16 +12 - (-30) = -4 +30 = 26
G = (3a+c)/d
G = (12+ 6)/-3 = 18/-3 = -6
H = -3ab +cd
H = - 3( -20) + -18
H = 60 -18 = 42
N°11
M = (-16 x25) /(-8 x -5)
M = (-2 x 5) / (-1x -1)
M = -10 / 1
M = 10
N = -5.6 x 0.25 x (-8)/-2 x 2.8
N = -2.8 x 0.25 x -8/-2 x 1
N = -5.6/-2
N = 2.8
N°12
2a -3 = -5a +11
2a +5a = 11 +3
7a = 14
a = 2
donc vrai pour a = 2
4b-2 = -b +1
4b +b = 1+2
5b = 3
b = 3/5 donc faux pour b = -1
C = 3c(2c-5) = d² +2
C = 6c² - 15c = d² +2
C = 150 - (75) = -4 +2
C = 75 = -2
donc non vérifiée
D = (2e+1)(e-3) = 2e² -5e -3 (pour e = -1.25)
D = ( - 2.5 +1) ( -1.25 -3) = -3.125 - (-6.25) -3
D = -1 x 3.75 = -3.125+6.25-3
D = -3.75 = 0.125 donc non vérifié
N)13
2/7 et 3/10 = 20/70 et 21/70
-2.3/2 et 3.61/5 = -11.5/10 et 7.22/10
1/2, -4/5 et 7/15 = 15/30, - 24/30 et 14/30
-10.34/24 et 15.2/16 = 20.68/48 et 62/48
5/6, 1/-12 et 5/24 = 20/24, -2/24 et 5/24
