Jawapan

2014-01-18T21:22:51+08:00
Tekan pakai kalkulator pun dapat.

7 x^{2}  + 2x + 1 = 0

(7 - ( - x) ) , (7 - (-x) ) = 0
(7 + x ) = 0 , (7+x)= 0
x = 
x = -1 per tujuh, x= -1 per tujuh