Sagot :
A(x) = (2x)² - 10² = (2x+10) (2x-10) = 4 (x+5) (x-5)
B(x) = (5+x) (1-2x+1-3x) = (5+x) (-5x+2)
C(x) = x² - 6x + 9
A(x) = 0 => (x+5) (x-5) = 0 => x = 5 ou -5
B(x) = 0 => (5+x) (-5x+2) = 0 => x = -5 ou x = 2/5
4x² - 100 = 4(x-3)²
4x² - 100 = 4 (x² - 6x + 9)
4x² - 100 = 4x² - 24x + 36
soit résoudre -24x + 36 = - 100
tu peux finir
bonjour
A(x) = 4 x² - 100,
A (x) = ( 2 x - 10 ) ( 2 x + 10 )
A = 0 pour x = 5 et - 5
A (x) = 69
4 x² - 100 = 69
4 x² = 69 + 100
4 x² = 169
x ² = 42.25
x = √42.25 ou - √ 42.25
x = 6.5 ou ( - 6.5 )
B (x) = (5 + x)(1 - 2 x) + (5 + x)(1 – 3 x)
B (x) = ( 5 + x ) ( 1 - 2 x + 1 - 3 x )
B (x) = ( 5 + x ) ( - 5 x + 2 )
B = 0 pour x = - 5 ou 2/5
et C(x) = (x - 3)² pour
C (x) = x² - 6 x + 9
4 x² - 100 = 4 ( x - 3 )²
4 x² - 100 = 4 ( x² - 6 x + 9 )
4 x² - 100 = 4 x² - 24 x + 36
4 x² - 4 x² + 24 x = 36 + 100
24 x = 136
x = 136/24 = 17/3
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