Toán Lớp 8: Tìm x,y
(3x-1)^2-(3x+2)(3x-2)=2020
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Toán Lớp 8: Tìm x,y
(3x-1)^2-(3x+2)(3x-2)=2020
Comments ( 2 )
$⇔ (3x)^2-2.3x+1-[(3x)^2-2^2]=2020$
$⇔ 9x^2-6x+1-9x^2+4=2020$
$⇔ -6x = 2020 – 1 – 4$
$⇔ – 6x= 2015$
$⇔$ x = {-2015}/{6}