Question

Calculati:
2x patrat+3x-1=0
X patrat-5=0
X patrat+10=0

Answer 1

$\displaystyle a).2x^2+3x-1=0 \\ a=2,b=3,c=-1 \\ \Delta=b^2-4ac=3^2-4 \cdot 2 \cdot (-1)=9+8=17 \\ x_1= \frac{-3+ \sqrt{17} }{2 \cdot 2} = \frac{-3+ \sqrt{17} }{4} \\ \\ x_2= \frac{-3- \sqrt{17} }{2 \cdot 2} = \frac{-3- \sqrt{17} }{4}$

$b).x^2-5=0 \\ x^2=0+5 \\ x^2=5 \\ x= \sqrt{5} \\ x=- \sqrt{5}$

$c).x^2+10=0 \\ x^2=0-10 \\ x^2=-10 \\ x=- \sqrt{10} \\ x= \sqrt{10}$