a) 3x(x+1) + (×-2)(3-x)
3x² +3x +3x -x² -6 +2x
2x² + 8x -6
b) (3t-5)²
9t² -2×3t×5 +25
9t² -30t +25
c) (x+10)(x-10) -100
x² -10x +10x -100 -100
x² -200
d) 3(x+5)²
3(x² +2×x×5 +25)
3(x² +10x +25)
3x² +30x +75
Bonjour,
a) 3x(x + 1) + (x-2)(3 - x)
= 3x² +3x + 3x -x² -6 +2x
=2x² +8x -6
b) (3t - 5)² =
IR (a-b)²
= 9t² -30t+25
c) (x + 10)(x - 10) - 100
IR (a-b) (a+b)
= x² -100 -100
= x² -200
d) 3(x + 5)²
IR (a+b)²
= 3* (x² +10x +25)
= 3x² +30x +75
