Question

[tex]x^{2} -3x-10=0
[/tex]

Answer 1

$\displaystyle x^2-3x-10=0 \\ a=1,b=-3,c=-10 \\ \Delta=b^2-4ac=3^2-4 \cdot 1 \cdot (-10)=9+40=49\ \textgreater \ 0 \\ x_1= \frac{3+ \sqrt{49} }{2 \cdot 1} = \frac{3+7}{2} = \frac{10}{2} =5 \\ \\ x_2= \frac{3- \sqrt{49} }{2 \cdot 1} = \frac{3-7}{2} = \frac{-4}{2} =-2 \\ \\ S=\{-2;5\}$

Answer 2

x²-3x-10=0 Δ=b²-4ac=(-3)² +4×10=49 X1= (-b +√Δ)/2a=( 3+7)/2×1= 10/2=5 X2=(-b-√Δ)/2a= (3-7)/2×1=-4/2=-2