bonjour
3 x = [ 2 ( x + 25) ] : 3
3 x = ( 2 x + 50 ) / 3
9 x / 3 = ( 2 x + 50 ) / 3
9 x = 2 x + 50
9 x - 2 x = 50
7 x = 50
x = 50/7
P triangle = 3 x 50/7 = 150 /7
P rectangle = 2 ( 50/7 + 25) = 100/7 + 50 = 100/7 + 350/7 = 450/7
150/7 x 3 = 450/7
Explications étape par étape
