bonjour
2 |2a +7|-|3b|+2|b+8|-|2b-a|
a ∈ [-2 ;5] et b ∈ à [-3;-1]
2a +7 >0 => 2a> -7 => a > -7/2 => a> -3,5
|2a +7| = 2a +7
b ∈ à [-3;-1]
3b = -3b
b+8 >0 => b > -8
|b+8| = b+8
2b-a < 0
|2b-a| = -2b+a
2 (2a +7)-(-3b) +2(b+8) -(-2b+a )
=4a+14 +3b +2b +16 +2b -a
= 3a +7b +30