Répondre :
Calculer, pour a = 2 :
E = 2a - 7
=2*2-7
=4-7= -3
F = - 3a ÷ 4 + 0,5
= -3*2/4+0.5
= -6/4+0.5
= -1.5+0.5
= -1
Calculer, pour b = -3 :
G = 4b + 2
=4*(-3)+2
= -12+2
= -10
H = 7 - b
=7-(-3)
=7+3
=10
E = 2a - 7
=2*2-7
=4-7= -3
F = - 3a ÷ 4 + 0,5
= -3*2/4+0.5
= -6/4+0.5
= -1.5+0.5
= -1
Calculer, pour b = -3 :
G = 4b + 2
=4*(-3)+2
= -12+2
= -10
H = 7 - b
=7-(-3)
=7+3
=10