Réponse :
1. LE PERIMETRE EST DE
[(x+5) + (2x -3)] X 2 = [x + 5 + 2x - 3] X 2 = ( 3x + 2) X 2 =6x + 4
L' AIRE EST DE
(x+5) X (2x - 3) = 2x² - 3x + 10x - 15 = 2x² + 7x - 15
2. x = 5
PERIMETRE = (6 X 5) + 4 = 34
[(5+5) + (2X5 -3)] X2 = [(10) + (10 - 3)] X2 = (10 + 7) X2 = 34
AIRE = (2X5²) - (3X5) + (10X5) - 15 = 50 - 15 + 50 - 15 = 70
[(5+5) X (2X5)-3 = [10 X (10-3)] = 10 X 7 = 70
Explications étape par étape