а) 2х²+5х-3 = (2х-1)(х+3)
б) х²+х-42 = (х-6)(х+7)
Объяснение:
а) 2х²+5х-3
2х²+5х-3 = 0
Д = 25+24 = 49 = 7²
х(1) = (-5+7) / 4 = 1/2
х(2) = (-5-7) /4 = -12/4 = -3
2х²+5х-3=2(х-1/2)(х+3) = (2х-1)(х+3)
б) х²+х-42
х²+х-42=0
Д = 1+168=169=13²
х(1) = (-1+13) / 2 = 6
х(2) = (-1-13) /2 = -7
х²+х-42=(х-6)(х+7)
2(х²+2*5/4*х+(5/4)²-(5/4)²-3/2)=
2((х+5/4)²-25/16-3/2)=
2((х+5/4)²-(25+24/16))=2((х+5/4)²-(7/4)²
2(х+5/4-7/4)(х+5/4+7/4)=
2(х-1/2)(х+3)
2)2х²+5х-3=0
Д=25+24=49=7²
х=(-5±7)/4
х1=-3;х2=1/2
2х²+5х-3=2(х+3)(х-1/2)
х²+х-42=0
Д=1+168=169=13²
х=(-1±13)/2
х1=-7;х2=6
х²+х-42=(х+7)(х-6)
а) 2х²+5х-3 = (2х-1)(х+3)
б) х²+х-42 = (х-6)(х+7)
Объяснение:
а) 2х²+5х-3
2х²+5х-3 = 0
Д = 25+24 = 49 = 7²
х(1) = (-5+7) / 4 = 1/2
х(2) = (-5-7) /4 = -12/4 = -3
2х²+5х-3=2(х-1/2)(х+3) = (2х-1)(х+3)
б) х²+х-42
х²+х-42=0
Д = 1+168=169=13²
х(1) = (-1+13) / 2 = 6
х(2) = (-1-13) /2 = -7
х²+х-42=(х-6)(х+7)