Х - 4y = 3
X = 4y + 3
X^2 = 16y^2 + 24y + 9
16y^2 + 24y + 9 - 21y = 28
16y^2 + 3y - 19 = 0
D = 9 + 1216 = 1225 ; V D = 35
y1 = ( - 3 + 35 ) : 32 = 1
y2 = ( - 3 - 35 ) : 32 = - 1,1875
X1 = 4•1 + 3 = 7
X2 = - 4,75 + 3 = - 1,75
Ответ ( 7 ; 1 ) ; ( - 1,75 ; - 1,1875 )