(5x-1)2+(5x+1)2-2(1-25x2)=25x2-10x+1+25x2+10x+1-2-50x2
= 0
Lời giải:
$(5x-1)^2+(5x+1)^2-2(1-25x^2)$
$=(5x-1)^2+(5x+1)^2-2(1-5x)(1+5x)$
$=(5x-1)^2+(5x+1)^2+2(5x-1)(5x+1)$
$=(5x-1+5x+1)^2$
$=(10x)^2=100x^2$
Ta có : \(\left(5x-1\right)^2-2\left(1-25x^2\right)+\left(5x+1\right)^2\)
\(=\left(5x-1\right)^2+2\left(25x^2-1\right)+\left(5x+1\right)^2\)
\(=\left(5x-1\right)^2+2\left(5x-1\right)\left(5x+1\right)+\left(5x+1\right)^2\)
\(=\left(5x-1+5x+1\right)^2=\left(10x\right)^2=100x^2\)
