1.3.
3-4 (2 )
: .
. .
, , ().
, , , , . , -.
- . , .
, .
() , .
:
= m-n
= amn
m =
m =
, - .
.
, , . .
:
2 b2 = (a-b)(a + b)
(a+b)2 =a2 +2 ab + b2
(a-b)2 =a2 -2 ab + b2-
a3 b3 = (a-b)(a2 + ab + b2)
a3 + b3 = (a+b)(a2 - ab + b2)
(a+b)3 =a3 +3a2 b +3a b2 +b3
(a-b)3 =a3 -3a2 b +3a b2 -b3
ax2 + bx + = 0 a(x x1)(x x2)
+ bx + = 0, ≠0
: D = - 4ac
D > 0, . - , :
X1,2 =
D = 0, .
D < 0, .
. x2 + px + q - 0 x, , :
x1 + x2 = - p; x1 x2 = q
:
+ = | - = | = | : = |
: = ad = bc
:
≥ 0; = ; = ; 2 = a2; =
:
|
|
a≥b b≤a;
a≥b b≥c a≥c;
0 a≥b a≥b
0 a≥b a≤b
a≥b a+ ≥b+
a≥b a- ≥b-
.
1. : S = x = , a≠b, ab 0
. , :
X 1 = -1 = =
a - b≠0, ; ab 0 .
, , .. x - 1 ;, x + 1 ;.
. :
S = = = = x +
x = = , S = + = + = +
ab 0, , = ab, S =
:
1) , .. , = S =
2) , .. , = S =
2. : .
. . : x1 =1; x2= 4, : = (x x1)(x x2) =(x 1)(x 4).
, :
= (x3 -x)- (4x2 -4) = x()- 4() = ()(x -4) = (x -1)(x +1)(x -4)
x≠1; x≠-1; x≠4 : = =
3. , : + , x1 x2 - 2x2 +6x +1 = 0 .
. + =
, : = ()(). :
()()= ()( - 3 ) = ()()2 - 3 )
. , 2x2 +6x +1 .
: = 62 -421 = 28 . , 2x2 +6x +1 = 0 , .
, = -3 =
, : + = = = -45
.
1. : :
2. x=31, y=21.
3. : : m =-3 n=7.
4. x=31, y=21.
5.
- + = 1
6. , = 10, : ) ; ) ; ) ;
7. b 3 + ?
.
1. .
2. .
3. .
4. .
5. .
6. .