D=7x-2x² =x(7-2x) 2) a) E=(x-1)(x-1)-x(x-2) =x²-2x+1-x²+2 =-2x+3 b) (10¹⁰-1)(10¹⁰-1)-10¹⁰(10¹⁰-2)=-2(10¹⁰)+3 3) a) F pour x=-1 f(-1)=(-2-7)(-2-7)-3(-4-14) =(-9)(-9)-3(-18) =81+54 =135 b) 4x-14=2(2x-7)
c) F=(2x-7)(2x-7)-6(2x-7) =(2x-7)(2x-7-6) =(2x-7)(2x-13)
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C=(2x-3)(4x-2)+(5x-6)(2x-3)
=(2x-3) (4x-2+5x-6)
=(2x-3)(9x-8)
D=7x-2x²
=x(7-2x)
2)
a) E=(x-1)(x-1)-x(x-2)
=x²-2x+1-x²+2
=-2x+3
b)
(10¹⁰-1)(10¹⁰-1)-10¹⁰(10¹⁰-2)=-2(10¹⁰)+3
3)
a) F pour x=-1
f(-1)=(-2-7)(-2-7)-3(-4-14)
=(-9)(-9)-3(-18)
=81+54
=135
b) 4x-14=2(2x-7)
c)
F=(2x-7)(2x-7)-6(2x-7)
=(2x-7)(2x-7-6)
=(2x-7)(2x-13)