Sagot :
Bonjour
A=(2t - 5)² + (2y - 5) (t - 1) + (2t - 5) (2t + 5)
A = 4t² - 20t + 25 + 2yt - 2y -5 t + 5 + 4t² - 25
A = 4t² + 4t² + 2yt - 20t - 5t - 2y + 25 - 25 + 5
A = 8t² + 2yt - 25t - 2y + 5.
Bonjour
A=(2t - 5)² + (2y - 5) (t - 1) + (2t - 5) (2t + 5)
A = 4t² - 20t + 25 + 2yt - 2y -5 t + 5 + 4t² - 25
A = 4t² + 4t² + 2yt - 20t - 5t - 2y + 25 - 25 + 5
A = 8t² + 2yt - 25t - 2y + 5.