Question

Учи ру! Помогите пж!!!! ​

Answer 1

$a^2x^2+bx+c=0\\\\4a^2x^2+4abx+4ac=0\\\\4a^2x^2+4abx+b^2=b^2-4ac\\\\(2ax)^2+2\cdot (2ax)\cdot b+b^2=b^2-4ac\\\\\underline {(2ax+b)^2=b^2-4ac\; }\\\\\\\star \; \; 2ax+b=\pm \sqrt{b^2-4ac}\\\\2ax=-b\pm \sqrt{b^2-4ac}\\\\x=\dfrac{-b\pm \sqrt{b^2-4ac}}{2a}$