Question

uma das raízes da equação 0,1x²-0,7x+1=0 é:

Answer 1

$0,1x^2-0,7x+1=0\\10(0,1x^2-0,7x+1)=(0)10\\x^2-7x+10=0\\\Delta=b^2-4ac=49-40=9\\x=\frac{-b\pm\sqrt{\Delta}}{2a}\\\\\boxed{x'=\frac{7+3}{2}=5}\\\\\\\boxed{x"=\frac{7-3}{2}=2}$