Impara online a risolvere i problemi di passo dopo passo. -z^2+9z+20. Applicare la formula: ax^2+bx+c=a\left(x^2+\frac{b}{a}x+\frac{c}{a}\right), dove a=-1, b=9, c=20 e x=z. Applicare la formula: a\left(x^2+b+c\right)=a\left(x^2+b+c+\left(\frac{coef\left(b\right)}{2}\right)^2-\left(\frac{coef\left(b\right)}{2}\right)^2\right), dove a=-1, b=-9z, c=-20 e x=z. Applicare la formula: a\left(x^2+b+c+f+g\right)=a\left(\left(x+\sqrt{f}sign\left(b\right)\right)^2+c+g\right), dove a=-1, b=-9z, c=-20, x^2+b=z^2-9z-20+\frac{81}{4}-\frac{81}{4}, f=\frac{81}{4}, g=-\frac{81}{4}, x=z e x^2=z^2. Applicare la formula: \frac{a}{b}+c=\frac{a+cb}{b}, dove a/b+c=\left(z- \frac{9}{2}\right)^2-20-\frac{81}{4}, a=-81, b=4, c=-20 e a/b=-\frac{81}{4}.

-z^2+9z+20