Bonsoir aidez moi j'ai besoin d'aide merci

Réponse:

A= (5x-3)²

= (5x)²- 2×5x×3 + 3²

= 25x² - 30x + 9

B= (10x - 6)(10x +6)

= (10x)² - 6²

= 100x² - 36

C= ( a + 7 ) ²

= a²+ 2×a×7 + 7²

= a²+ 14a + 49

D= (11+ 8x)²

= 11² + 2×11×8x + (8x)²

= 121 + 176x + 64x²

E= (9n -2)²

= (9n)² - 2×9n×2 + 2²

= 81n²- 36n + 4

F= (9+2x) (9-2x)

= 9²- (2x)²

= 81 - 4x²

G= (20a- b) (b+20a)

= (20a)²- b²

= 400a²-b²

H= (4x -7)²

= (4x)² - 2×4x×7 + 7²

= 16x²- 56x + 49

I= (100+ 3y)²

= 100² + 2×100×3y + ( 3y)²

= 10000+ 600y+ 9y²