bonjour
A = 3 ( x² - 5 x + x - 5 )
= 3 x² - 15 x + 3 x - 15
= 3 x² - 12 x - 15
B = 2 ( - 3 t + 21 - t² + 7 t )
= - 6 t + 42 - 2 t² - 14 t
= - 2 t² - 20 t + 42
C = - ( 3 y² - 6 y + 15 y - 30 )
= - 3 y² + 6 y - 15 y + 30
= - 3 y² - 9 y + 30
D = 2 ( 4 x - 2 x² - 10 + 5 x )
= 8 x - 4 x² - 20 + 10 x
= - 4 x² + 18 x - 20
