Tìm x biết, X+1/125+x+2/124+x+3/123+x+4/122+x+146/5=0
\(\frac{x+1}{125}+\frac{x+2}{124}+\frac{x+3}{123}+\frac{x+4}{122}+...+\frac{x+146}{5}=0\)
Tìm x biết :\(\frac{x+1}{125}+\frac{x+2}{124}+\frac{x+3}{123}+\frac{x+4}{122}+\frac{x+126}{5}=0\)
\(\frac{x+1}{125}+\frac{x+2}{124}+\frac{x+3}{123}+\frac{x+4}{122}+\frac{x+146}{5}=0\)
\(\left(\frac{x+1}{125}+1\right)+\left(\frac{x+2}{124}+1\right)+\left(\frac{x+3}{123}+1\right)+\left(\frac{x+4}{122}+1\right)+\left(\frac{x+146}{5}-4\right)=0\)
\(\frac{x+126}{125}+\frac{x+126}{124}+\frac{x+126}{123}+\frac{x+126}{122}+\frac{x+126}{5}=0\)
\(\left(x+126\right).\left(\frac{1}{125}+\frac{1}{124}+\frac{1}{123}+\frac{1}{122}+\frac{1}{5}\right)=0\)
vì \(\left(\frac{1}{125}+\frac{1}{124}+\frac{1}{123}+\frac{1}{122}+\frac{1}{5}\right)\ne0\)nên x + 126 = 0 \(\Rightarrow\)x = -126
\(\dfrac{x+1}{124}\)+\(\dfrac{x+2}{123}\)=\(\dfrac{x+3}{122}\)+\(\dfrac{x+4}{121}\)
\(\dfrac{x+1}{124}+1+\dfrac{x+2}{123}+1=\dfrac{x+3}{122}+1+\dfrac{x+4}{121}+1\)
\(\Leftrightarrow\dfrac{x+125}{124}+\dfrac{x+125}{123}=\dfrac{x+125}{122}+\dfrac{x+125}{121}\)
\(\Leftrightarrow\left(x+125\right)\left(\dfrac{1}{124}+\dfrac{1}{123}-\dfrac{1}{122}-\dfrac{1}{121}\ne0\right)=0\Leftrightarrow x=-125\)
<=>\(\dfrac{x+1}{124}+\dfrac{x+2}{123}-\dfrac{x+3}{122}-\dfrac{x+4}{121}=0\)
<=>\(\left(\dfrac{x+1}{124}+1\right)+\left(\dfrac{x+2}{123}+1\right)-\left(\dfrac{x+3}{122}+1\right)-\left(\dfrac{x+4}{121}+1\right)=0\)
<=>\(\dfrac{x+125}{124}+\dfrac{x+125}{123}-\dfrac{x+125}{122}-\dfrac{x+125}{121}=0\)
<=>\(\left(x+125\right)\left(\dfrac{1}{124}+\dfrac{1}{123}-\dfrac{1}{122}-\dfrac{1}{121}\right)=0\)
<=>x+125=0
<=>x=-125
Tính nhanh
175+(-24)+(-125)+(-36)
-141+(-34)-(-41)-(-54)
-123-(49-123+51)
-28-(-15)-(-28)-(-85)
-78.21+(-21):122
-25.(-13).(-4)
-125.(-54).8
Tìm số nguyên x,y
x.(x-2)=-1
x(x-y)=5
x.(x+y)=2
Giải nhanh giúp em ạ<3
Bài 5:
a) \(\dfrac{x+1}{99}+\dfrac{x+4}{96}+\dfrac{x+8}{92}+\dfrac{x+3}{97}+4=0\)
b) \(\dfrac{x-11}{111}+\dfrac{x-12}{112}=\dfrac{x-23}{123}+\dfrac{x-24}{124}\)
\(\Leftrightarrow\left(\dfrac{x-11}{111}+1\right)+\left(\dfrac{x-12}{112}+1\right)=\left(\dfrac{x-23}{123}+1\right)+\left(\dfrac{x-24}{124}+1\right)\)
=>x+100=0
=>x=-100
a: =>\(\left(\dfrac{x+1}{99}+1\right)+\left(\dfrac{x+4}{96}+1\right)+\left(\dfrac{x+8}{92}+1\right)+\left(\dfrac{x+3}{97}+1\right)=0\)
=>x+100=0
=>x=-100
b: =>(x-11/111+1)+(x-12/112+1)=(x-23/123+1)+(x-24/124+1)
=>x+100=0
=>x=-100
tính nhanh:
(1/2+2/3+3/4+4/5+...+122/123+123/124).(125-5.25)
(1/2+2/3+3/4+4/5+...+122/123+123/124).(125-5.25)
=(1/2+2/3+3/4+4/5+...+122/123+123/124).(125-125)
=(1/2+2/3+3/4+4/5+...+122/123+123/124).0=0
Tìm x biết
a, (x+1) . (x^2-4) =0
b, x^15 = x
c, (x-5)^4 = (x-5)^6
d, (2.x+1)^3 =125
bài 50:tìm số nguyên x biết
a,|x-47|-115=0
b,315+(146-x)=401
c,(3x-6).3=34
d,4.2x-3=125
|x-47|-115=0
\(\Rightarrow\left|x-47\right|=115\)
\(\Rightarrow x-47=115\) hoặc \(x-47=-115\)
\(\Rightarrow x=115+47\) \(x=-115+47\)
\(\Rightarrow x=162\in Z\) \(x=-68\in Z\)
Vậy \(x\in\left\{162;-68\right\}\)
Mấy phần khác dễ rồi nên bạn tự làm nha
Chúc bn học tốt
a,|x-47|-115=0
|x-47|=115
\(\Rightarrow\orbr{\begin{cases}x-47=115\Rightarrow x=115+47=162\\x-47=-115\Rightarrow x=-115+47=-68\end{cases}}\)
Vậy.................................................
b,315+(146-x)=401
146-x=401-315
146-x=86
x=146-86
x=60
Vậy x=60
c,(3x-6).3=34
(3x-6).3=81
3x-6=81:3
3x-6=27
3x=27+6
3x=33
x=33:3
x=11
Vậy x=11
d,4.2x-3=125
4.2x=125+3
4.2x=128
2x=128:4
2x=32
2x=25
=> x=5
Vậy x=5
Tích sau có tận cùng là bao nhiêu chữ số 0
25 x 26 x 27x......x 123 x 124 x 125 .