1) (7-(-3.5))(7+(-3.5))+((-3.5)+3)²=
=(7+3.5)(7-3.5)+(-0.5)²=37
2(x-2)(x+2)-(x-1)²=x²-5
1) (x-1)²=(x-1)(x-1)=x²-x-x+1=x²-2x+1
2) (x-2)(x-2)=x²-2x-2x+4=x²-4x+4
3) 2(x²-4x+4)=2x²-8x+8
2x²-8x+8-x²+4x-4-x²+5=0
-4x+9=0
-4x=-9
x=-9/(-4)=2.25
6+4=10
3+4=7
10-7=3
вот и ответ
Д=в²-4ас= -8²-4•15=64-60=4
х1=(-в+√Д)/2а=(8+2)/2=5
х2=(-в-√Д)/2а=(8-2)/2=3
х1+х2=5+3=8
1) (х-4)/(х^0,5+2)+2=(х^0,5-2)(х^0,5+2)/((х^0,5+)+2=х^0,5-2+2=х^0,5
2) 1/2х-х*1/2=0
(1-х^2)/2х=0
1-х^2=0
х^2=1
х1=1
х2=-1