Question

a -2a+1= quero saber como resolver essa questão 

Answer 1

a-2a+1=0
-a= -1eu acho n tenho certesa :D

Answer 2

$a^2-2a+1=0\\\\ \Delta=b^2-4\cdot a\cdot c\\ \Delta=(-2)^2-4\cdot1\cdot1\\ \Delta=4-4\\\Delta=0\\\\a=\dfrac{-b\pm\sqrt{\Delta}}{2a}=\dfrac{2\pm\sqrt{0}}{2\cdot1}=\dfrac{2}{2}=1\\\\\boxed{a=1}\\\\S=\{1\}$

Então a=1