4 years ago

Garrrrryy no need to show work two questions thankks

1 answer:

8 0

1. $x^2-x-72=0$
$\Delta=(-1)^2-4*1*(-72)=1+288=289$
$\sqrt{\Delta}=17$
$x_1=\frac{1-17}{2}=-8$
$x_2=\frac{1+17}{2}=9$

2. $f(x)=x^2+12x+20$
$\Delta=144-80=64$
$\sqrt{\Delta}=8$
$x_1=\frac{-12-8}{2}=-10$
$x_2=\frac{-12+8}{2}=-2$

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