Sagot :
1) a) -5(4x-3)
-20x+15
b) -5x(2-x)
-10x+5x²
c) (7x-9)(3-8x)
21x-56x²-27+72x
-56x²+93x-27
2)f) (8x+3)²
64x²+48x+9
g) (9-x)²
81-18x+x²
h) (5x-2)(5x+2)
25x²+10x-10x-4
25x²-4
-20x+15
b) -5x(2-x)
-10x+5x²
c) (7x-9)(3-8x)
21x-56x²-27+72x
-56x²+93x-27
2)f) (8x+3)²
64x²+48x+9
g) (9-x)²
81-18x+x²
h) (5x-2)(5x+2)
25x²+10x-10x-4
25x²-4
1)
A = -5 * (4x - 3)
A = -5 * 4x - (-5) * 3
A = -20x - (-15)
A = -20x + 15
B = -5x * (2 - x )
B = -5x * 2 - (-5x) * x
B = -10x - (-5x²)
B = 5x² - 10x
C = (7 * (-9) ) * (3 - 8x)
C = 7 * 3 - 7 * 8x + (-9) * 3 - (-9) * (-8x)
C = 21 - 56x + (-27) - 72x
C = -128x -6
2)
F = (8x + 3)²
F = 64x² + 9
G = (9 - x)²
G = 81 - x²
H = (5x - 2) * (5x + 2)
H = 5x * 5x + 5x * 2 - 2 * 5x + 2 * 2
H = 25x² + 10x - 10x + 4
H = 25x² + 4
A = -5 * (4x - 3)
A = -5 * 4x - (-5) * 3
A = -20x - (-15)
A = -20x + 15
B = -5x * (2 - x )
B = -5x * 2 - (-5x) * x
B = -10x - (-5x²)
B = 5x² - 10x
C = (7 * (-9) ) * (3 - 8x)
C = 7 * 3 - 7 * 8x + (-9) * 3 - (-9) * (-8x)
C = 21 - 56x + (-27) - 72x
C = -128x -6
2)
F = (8x + 3)²
F = 64x² + 9
G = (9 - x)²
G = 81 - x²
H = (5x - 2) * (5x + 2)
H = 5x * 5x + 5x * 2 - 2 * 5x + 2 * 2
H = 25x² + 10x - 10x + 4
H = 25x² + 4