Toán Lớp 8: (2x-1)(2x+1)-(2x-1)^2
(x+3)(x-5)+(x-4)^2
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Toán Lớp 8: (2x-1)(2x+1)-(2x-1)^2
(x+3)(x-5)+(x-4)^2
Comments ( 2 )
$=(2x-1)[(2x+1)-(2x-1)]$
$=(2x-1)(2x+1-2x+1)$
$=2(2x-1)$
$=(x+3)(x-5)+(x-4)(x-4)$
$=(x+3-1)(x-5+1)+(x-4)(x-4)$
$=(x+2)(x-4)+(x-4)(x-4)$
$=(x-4)[(x+2)+(x-4)]$
$=(x-4)(x+2+x-4)$
$=(x-4)(2x-2)$
$=2(x-4)(x-1)$