2x^2 - 3x - 7 = 0
(x1)^2 + (x2)^2 = ?
2 = a
-3 = b
-7 = c
x1 + x2 = -b/a
x1*x2 = c/a
(x1 +x2)^2 = (-b/a)^2
(x1)^2 + (x2)^2 + 2*x1*x2 = (-b/a)^2
(x1)^2 + (x2)^2 + 2*(-7/2) = 9/4
(x1)^2 + (x2)^2 - 7 = 9/4
(x1)^2 + (x2)^2 = 37/4
4х^2+6х+16х+24-(4х^2+4х+1)
4х^2+6х+16х+24-4х^2-4х-1
в скобках
-(17/9+19/6)=-((34+57)/18)=-91/18
далее умножаем
-91/18*8 64/100=-91/18*864/100=-78624/1800=-43,68