Toán Lớp 8: Bài 1 : Thực hiện phép tính
a) ( 2 x + 5 ) ( 3 x + 1 )
b) ( x – 1 ) ( x^2 + x + 1 )
c) ( x – 2 )^2 + x ( 2 x + 2 )
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Toán Lớp 8: Bài 1 : Thực hiện phép tính
a) ( 2 x + 5 ) ( 3 x + 1 )
b) ( x – 1 ) ( x^2 + x + 1 )
c) ( x – 2 )^2 + x ( 2 x + 2 )
Comments ( 2 )
=6x^2+2x+15x+5
=6x^2+17x+5
b)(x-1)(x^2+x+1)
=(x-1)[(x)^2+(x)(1)+(1)^2]
=(x)^3-(1)^3
=x^3-1
c)(x-2)^2+x(2x+2)
=(x)^2-2(x)(2)+(2)^2+2x^2+2x
=x^2-4x+4+2x^2+2x
=x^2+2x^2-4x+2x+4
=3x^2-2x+4