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6 tháng 12 2018

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Câu 1 The function mm is defined on the real numbers by m(k) = \dfrac{k+2}{k+8}m(k)= k+8 k+2 ​ . What is the value of 10\times m(2)10×m(2)? Answer: Câu 2 The function ff is defined on the real numbers by f(x)= ax-3f(x)=ax−3. What is the value of a if f(3)=9f(3)=9? Answer: Câu 3 The function ff is defined on the real numbers by f(x)= 2x+a-3f(x)=2x+a−3. What is the value of a if f(-5)=11f(−5)=11? Answer: Câu 4 The function ff is defined on the real numbers by f(x) = 2 +...
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Câu 1 The function mm is defined on the real numbers by m(k) = \dfrac{k+2}{k+8}m(k)= k+8 k+2 ​ . What is the value of 10\times m(2)10×m(2)? Answer: Câu 2 The function ff is defined on the real numbers by f(x)= ax-3f(x)=ax−3. What is the value of a if f(3)=9f(3)=9? Answer: Câu 3 The function ff is defined on the real numbers by f(x)= 2x+a-3f(x)=2x+a−3. What is the value of a if f(-5)=11f(−5)=11? Answer: Câu 4 The function ff is defined on the real numbers by f(x) = 2 + x-x^2f(x)=2+x−x 2 . What is the value of f(-3)f(−3)? Answer: Câu 5 Given a real number aa and a function ff is defined on the real numbers by f(x)=-6\times|3x|-4f(x)=−6×∣3x∣−4. Compare: f(a)f(a) f(-a)f(−a) Câu 6 There are ordered pairs (x;y)(x;y) where xx and yy are integers such that \dfrac{5}{x}+\dfrac{y}{4}=\dfrac{1}{8} x 5 ​ + 4 y ​ = 8 1 ​ Câu 7 Given a negative number kk and a function ff is defined on the real numbers by f(x)=\dfrac{6}{13}xf(x)= 13 6 ​ x. Compare: f(k)f(k) f(-k)f(−k) Câu 8 Given a positive number kk and a function ff is defined on the real numbers by f(x)=\dfrac{-3}{4}x+4f(x)= 4 −3 ​ x+4. Compare: f(k)f(k) f(-k)f(−k). Câu 9 A=(1+2+3+\ldots+90) \times(12 \times34-6 \times 68):(\dfrac{1}{3}+\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{1}{6})=A=(1+2+3+…+90)×(12×34−6×68):( 3 1 ​ + 4 1 ​ + 5 1 ​ + 6 1 ​ )= Câu 10 Given that \dfrac{2x+y+z+t}{x}=\dfrac{x+2y+z+t}{y}=\dfrac{x+y+2z+t}{z}=\dfrac{x+y+z+2t}{t} x 2x+y+z+t ​ = y x+2y+z+t ​ = z x+y+2z+t ​ = t x+y+z+2t ​ . The negative value of \dfrac{x+y}{z+t}+\dfrac{y+z}{t+x}+\dfrac{z+t}{x+y}+\dfrac{t+x}{y+z} z+t x+y ​ + t+x y+z ​ + x+y z+t ​ + y+z t+x ​ is

2
28 tháng 2 2018

nhanh đi nhé

1 tháng 11 2019

KHO QUÁ ĐI

13 tháng 1 2019

Bài 1 :

Theo thứ tự tăng dần : -|-2015| ; -11 ; -10 ; -|-9| ; 0 ; 10 ; 12 ; 23.

Bài 2 :

a) 1125 - ( 374 + 1125 ) + ( - 65 + 374 )

= 1125 - 374 - 1125 + ( -65 ) + 374

= ( 1125 - 1125 ) + [ ( -374 ) + 374 ] + ( -65 )

= 0 + 0 + ( -65 )

= -65

b) -23 . 63 + 23 . 21 - 58

= ( -23 + 23 ) . ( 63 + 21 - 58 )

= 0 . 26

= 0

c) -2003 + ( -21 + 75 + 2003 )

= (-2003 ) + ( -21 ) + 75 + 2003

= [ ( -2003 ) + 2003 ] + [ ( -21 ) + 75 ]

= 0 + 54

= 54

d) 942 - 2567 + 2563 - 1942

= ( 942 - 1942 ) - ( 2567 - 2563 )

= (-1000 ) - 4

= - 1004

e) 12 - 12 + 11 + 10 - 9 + 8 - 7 + 5 - 4 + 3 + 2 - 1

= ( 12 - 12 ) + 11 + ( 10 - 9 ) + ( 8 - 7 ) + ( 5 - 4 ) + 3 + ( 2 - 1 )

= 0 + 11 + 1 + 1 + 1 + 3 + 1

= 18

13 tháng 1 2019

hahahahahaha

15 tháng 6 2022

a: =>3x+17=14

=>3x=-3

hay x=-1

b: =>|x+9|=-8(vô lý)

c: =>3x+2=17

=>3x=15

hay x=5

d: \(\Leftrightarrow\left(x-2\right)\left(x+2\right)\cdot3\cdot\left(2-x\right)=0\)

hay \(x\in\left\{2;-2\right\}\)

e: =>2x+4=0

hay x=-2

f: =>2|2x-1|=34

=>|2x-1|=17

=>2x-1=17 hoặc 2x-1=-17

=>2x=18 hoặc 2x=-16

=>x=9 hoặc x=-8

5 tháng 10 2021

a) \(X+3=12\Leftrightarrow X=12-3\Leftrightarrow X=9\)

b) \(N+10=5\Leftrightarrow N=5-10\Leftrightarrow N=-5\)

c)\(N+12=3\Leftrightarrow N=3-12\Leftrightarrow N=-9\)

d)\(X+9=-8\Leftrightarrow X=-8-9\Leftrightarrow X=-17\)

e)\(N+\left(-5\right)=-12\Leftrightarrow N-5=-12\Leftrightarrow N=-12+5\Leftrightarrow N=-7\)

f)\(T+20=30\Leftrightarrow T=30-20\Leftrightarrow T=10\)

g)\(Q+3=0\Leftrightarrow Q=0-3\Leftrightarrow Q=-3\)

h)\(N+6=-12\Leftrightarrow N=-12-6\Leftrightarrow N=-18\)

i)\(Y+\left(-2\right)=-10\Leftrightarrow Y-2=-10\Leftrightarrow Y=-10+2\Leftrightarrow Y=-8\)

j)\(T+\left(-7\right)=0\Leftrightarrow T-7=0\Leftrightarrow T=0+7\Leftrightarrow T=7\)

15 tháng 11 2023

a) - 3 ∉ N

b) 5 ∈ Z 

c) 0 ∈ Z 

d) 1 ∈ N 

e) - 7 ∈ Z 

f) 0 ∈ N 

g) - 1 ∉ N 

h) - 10 ∈ Z 

5 tháng 6 2022

a: \(f\left(1\right)=\dfrac{1-1}{1-2}=-1\)

\(f\left(-1\right)=\dfrac{-1-1}{-1-2}=-\dfrac{2}{-3}=\dfrac{2}{3}\)

\(f\left(0\right)=\dfrac{0-1}{0-2}=\dfrac{1}{2}\)

\(f\left(2\right)=\dfrac{2-1}{2-2}=\varnothing\)

b: f(x)=2 nên x-1=2x-4

=>2x-4=x-1

=>x=3

c: Để y là số ngyên thì \(x-2+1⋮x-2\)

\(\Leftrightarrow x-2\in\left\{1;-1\right\}\)

hay \(x\in\left\{3;1\right\}\)

27 tháng 11 2017

Giỏi quá ha!!!oe

27 tháng 11 2017

\(y=f\left(x\right)=\dfrac{x-1}{x-2}\)

a)

\(y=f\left(1\right)=\dfrac{1-1}{1-2}=\dfrac{0}{-1}=0\)

\(y=f\left(-1\right)=\dfrac{\left(-1\right)-1}{\left(-1\right)-2}=\dfrac{-1-1}{-1-2}=\dfrac{-\left(1+1\right)}{-\left(1+2\right)}=\dfrac{-2}{-3}=\dfrac{2}{3}\)

\(y=f\left(0\right)=\dfrac{0-1}{0-2}=\dfrac{-1}{-2}=\dfrac{1}{2}\)