developper et reduire A(x)= ( 3x-2)²-3(x+2)(4x-3) B(x) = (x+5)(x-5)+3(x+1)² factoriser : C(x)= 16(x-1)²-(2x-5)² D(x)=2(4x+5)(3x+7)+(3x+7)(2x-5) Resoudre : a)2(x
Mathématiques
Antonia96
Question
developper et reduire
A(x)= ( 3x-2)²-3(x+2)(4x-3)
B(x) = (x+5)(x-5)+3(x+1)²
factoriser :
C(x)= 16(x-1)²-(2x-5)²
D(x)=2(4x+5)(3x+7)+(3x+7)(2x-5)
Resoudre :
a)2(x-√ 2)>=√ 2-5x
b)x/3 - 8-2x/7< -2
A(x)= ( 3x-2)²-3(x+2)(4x-3)
B(x) = (x+5)(x-5)+3(x+1)²
factoriser :
C(x)= 16(x-1)²-(2x-5)²
D(x)=2(4x+5)(3x+7)+(3x+7)(2x-5)
Resoudre :
a)2(x-√ 2)>=√ 2-5x
b)x/3 - 8-2x/7< -2
1 Réponse
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1. Réponse amjsalido
A(x)=(3x-2)²-3(x+2)(4x-3)=9x²-12x+4-3(4x²-3x+8x-6)=9x²-12x+4-12x²+9x-24x+18=)
B(x)=(x+5)(x-5)+3(x+1)²=x²-25+3(x²+2x+1)=x²-25+3x²+6x+3=4x²+6x-22)
C(x)=16(x-1)²-(2x-5)²=[4(x-1)+(2x-5)][4(x-1)-(2x-5)]=(4x-4+2x-5)(4x-4-2x+5)=(6x-9)(2x+ 1)
D(x)=(3x+7)[2(4x+5)+(2x-5)]=(3x+7)(8x+10+2x-5)=(3x+7)(10x+5)
2(x-V2)=V2-5x 2x-2V2=V2-5x 2x+5x=V2+2V2 7x=3V2 x=3V2/7
x/3-8-2x/7<-2 x/3-2x/7<-2+8 (7x-6x)/21<6 x/21<6 x<126