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
