1)x²=25
x=-5 U x=5
2)x²=7
x=-√7 U x=√7
3)x²=-8
x∈∅
6х^2-7х+4-4х^2+4х-18=2х^2-3х-14
.........................
X²+10x-2000=(x+50)(x-40)
ax²+bx+c)=a(x-x1)(x-x2)
x1+x2=-10 U x1*x2=-2000
x1=-50 U x2=40
1) ( 7 + x)^2 = 49 + 14x + x^2
2) (2x - 3)^2 = 4x^2 - 12x + 9
3) (x^2 + 4)^2 = x^4 + 8x^2 + 16
4) ( n + 5)(n - 5) = n^2 - 25
5) (5k - 2n)(5k + 2n) = 25k^2 - 4n^2
6) (1/4n^2 + 2/5)(1/4n^2 - 2/5) = 1/16n^4 - 4/25