Bonsoir;
A = (9 x − 8)²
= 81x² - 144x +64
B = (7 x − 5) × (7 x + 5)
= 49x² -25
C = (5 x + 4)²
= 25x² +40x +16
D = (9 x + 1) × (x − 9)
= 9x² -81x +x -9
= 9x² -80x -9
E = − (10 x − 9)²
= -( 100x² -90x +81)
= -100x² +90x -81
F = 8 x + 2 7 × 8 x − 2 7
= 8x + 216x -27
= 224x -27