4х - y = 1
y = 4x - 1
y^2 = 16x^2 - 8x + 1
y^2 - 10x^2 = 10x + 25
16x^2 - 8x + 1 - 10x^2 = 10x + 25
6x^2 - 8x + 1 - 10x - 25 = 0
6x^2 - 18x - 24 = 0
6•( x^2 - 3x - 4 ) = 0
D = 9 + 16 = 25 ; V D = 5
x1 = ( 3 + 5 ) : 2 = 4
x2 = ( 3 - 5 ) : 2 = - 1
y = 4x - 1
y1 = 4•4 - 1 = 15
y2 = 4•( - 1 ) - 1 = - 5
Ответ ( 4 ; 15 ) ; ( - 1 ; - 5 )
Надо: 68*373=25364
потом: 68*673-25364=20400
ВРОДЕ ТАК!!
А)6/14; 9/21; 12/28
в)4/10; 6/15; 8/20
c)14/22; 21/33; 28/44
р)128/168; 192/252; 256/336
д)150/250; 225/375; 300/500