Sagot :
Bonjour,
■ Développer, réduire et ordonne :
(4 - 4y)(2y - 5) = 8y - 20 - 8y² + 20y = -8y² + 28y - 20
(8 - 5z)(-z + 1) = -8z + 8 + 5z² - 5z = 5z² - 13z + 8
(4-4Y)(2Y-5)
=(4×2Y)-(4×5)-(4Y×2Y)+(4Y×5)
=8Y-20-8Y^2+20 Y
=8Y^2-28Y-20
(8-5Z)(-Z+1)
=-(8×Z)+(8×1)+(5Z×Z)-(5Z×1)
=-8Z+8+5Z^2-5Z
=-13Z+5Z^2+8