bonjour
A= 2 ( 3 + 2 x ) + 5 x
= 6 + 4 x + 5 x
= 9 x + 6
B= 4 ( - 5 x + y) + 5 ( 8 x - 4 )
= - 20 x + 4 y + 40 x - 20
= 20 x + 4 y - 20
C= 10 ( 2.4 + 5.3 ) + x ( 3 - y )
= 24 + 53 + 3 x - xy
= - xy + 3 x + 77
D= 2.7 ( 100 - 10 x ) - x ( 3 - 2 x ) + x²
= 270 - 27 x - 3 x + 2 x² + x²
= 3 x² - 30 x + 270