Réponse :
Re bonjour, pour moi il y a une erreur dans l'énoncé (there is a mistake in the subject). you must read :the perimeter is 60cm and not 160cm
Explications étape par étape :
a)You can write
x+y+25=60 (equation 1)
x²+y²=25² (equation 2) due to the Pythagore th.
from (1) y =35-x
you report in (2)
x²+(35-x)²=25²
x²+x²-70x+35²-25²=0
2x²-70x+600=0 or 2(x²-35x+300)=0
you have to solve
x²-35x+300=0
delta=35²-1200=25
solutions: x1=(35+5)/2=20 et x2=(35-5)/2=15
So for the triangle x=20 cm and y=15 cm
b)The aera is A=20*15/2=150cm²
