Question

calculati dupa urmatoarea regula: x=a
a)2x²+5=7
b)4x²-2=0
c)19x²+18=17
d)2x²=1-(-1) la puterea 2010

Answer 1

Te ajut la a si la b !
a) 2x^2 = 2 <=> x^2 = 1 <=> /x/ = 1 <=> x = - 1 ; x = + 1 ;
b) 4x^2 = 2 <=> x^2 = 1 / 2  <=> / x / = $\frac{ \sqrt{2} }{2}$ <=>
 x = + $\frac{ \sqrt{2} }{2}$ ; x = - $\frac{ \sqrt{2} }{2}$ ;

Bafta !