1)
-х - 3у - 4 + 2у =
- х
–у - 4
при х=(-15),
у=(-4)
-(-15) –(-4) – 4
= 15 + 4 - 4 =
15
<span>
2)
2pq - 2p - p + 2q =
2pq - 3p + 2q</span>
<span>при p=(-3), q=(-7)</span>
<span>2 </span>·<span>(-3)</span>·<span>(-7) - 3</span>·<span>(-3) + 2</span>·<span>(-7) = 42 + 9 - 14 =
37
</span>
<span>
3)
3uv</span>³<span> + u</span>²<span>v</span>²<span> -2uv</span>³<span> + u</span>³<span>v – u</span>⁴<span> =</span>
uv³ + u²v² + u³v – u⁴ <span> при u=1; v=(-1)</span>
1·(-1)³ + 1² · (-1)² + 1³·(-1) <span>– 1</span>⁴<span> = -1 + 1 - 1 - 1 = - 2 </span>
Q=b2/b1=-2/8=-1/4 проверим -2*(-1/4)=1/2 все так.
B(n-1)=(n-1)²+1=n²-2n+2
b(n)=n²+1
b(n+1)=(n+1)²+1=n²+2n+2
А1.
1) x - <u> 5x </u> = <u>x(x+2)-5x </u>=<u> x² +2x-5x </u>= <u>x² -3x</u> =<u>x(x-3)</u>
x+2 x+2 x+2 x+2 x+2
2) <u> x(x-3)</u> : <u> x-3 </u>= <u> x(x-3)</u> * <u>x+2 </u> = x
x+2 x+2 x+2 x-3
Ответ: 2)
А2.
1)<u> 3a² </u> * <u> b </u>= <u>a </u>
b² 6a 2b
2) <u>a+8b</u> - <u>a </u>= <u>a+8b-a</u> =<u> 8b </u> =4
2b 2b 2b 2b
Ответ: 2)
А3.
a = <u> 3 </u>= <u> 3 </u> = <u> 3*18 </u> = <u> 54 </u> =4 ¹⁰/₁₁
<u>1 </u>+ <u>1 </u>+ <u>1 </u> <u> 6+3+2</u> 11 11
3 6 9 18
Ответ: 1)
А4.
1) <u> x </u> - <u>1 </u>= <u>x² -y² </u>= <u>(x-y)(x+y)</u>
y² x xy² xy²
2) <u>1 </u> - <u> 1 </u>= <u> x-y</u>
y x xy
3)<u> (x-y)(x+y)</u> : <u> x-y </u> = <u>(x-y)(x+y)</u> *<u> xy </u>=<u> x+y</u>
xy² xy xy² x-y y
Ответ: 3)
В1.
1) <u> 1 </u> - <u> 1 </u> - <u> 1 </u> =
(a-x)(x-1) (a-x)(a-1) (a-1)(x-1)
=<u> a-1-(x-1)-(a-x) </u> = <u> a-1-x+1-a+x </u> = <u> 0 </u> = 0
(a-x)(x-1)(a-1) (a-x)(x-1)(a-1) (a-x)(x-1)(a-1)
2) 0 * <u> a³-8x³ </u>= 0
a⁴+b⁴
Ответ: 0.
В2.
y= <u>2m </u> - x
3c
<u>2m </u>= y+x
3c
2m =3c(y+x)
m = <u>3c(x+y)</u>
2
m= 1.5c(x+y)
Ответ: 1,5c(x+y)
x1²-x2²=24
x²-6x+c=0
D=36-4c √D=2√(9-c)
x1=(6+2√(9-c))/2 x2=(6-2√(9-c))/2
x1=3+√(9-c) x2=3-√(9-c)
(3+√(9-c))²-(3-√(9-c))² =24
(3+√(9-c)-3+√(9-c))*(3+√(9-c)+3-√(9-c))=24
2√(9-c) *6=24
12√(9-c)=24
√(9-c)=2
9-c=4
c=9-4
c=5
ответ: с=5