a*(-14)*a + 49
(a*(-14))*a + 49 при a = 1/2
(a*(-14))*a + 49
((1/2)*(-14))*(1/2) + 49
((-14)/2)/2 + 49
91/2
2 49 - 14*a
49.0 - 14.0*a^2
/ 2\ 7*\7 - 2*a /
/ 2\ -7*\-7 + 2*a /