\(B=\frac{2^{13}+2^5}{2^{10}+2^2}\) \(C=\frac{21^2\cdot14\cdot125}{35^3\cdot6}\)
mk cần gấp mong mn giúp đỡ. mk sẽ tk
\(\frac{21^2\cdot14\cdot125}{35^3\cdot6}=?\)
Ta có :
\(\frac{21^2.14.125}{35^3.6}=\frac{3^2.7^2.2.7.5^3}{5^3.7^3.2.3}=\frac{2.3^2.5^3.7^3}{2.3.5^3.7^3}=\frac{3}{1}=3\)
Vậy \(\frac{21^2.14.125}{35^3.6}=3\)
\(\frac{21^2.14.125}{35^3.6}\)= \(\frac{21^2.2.7.125}{42875.2.3}\)= \(\frac{21^2.7.125}{125.343.3}\)= \(\frac{21^2.7.125}{125.7.49.3}\)= \(\frac{21^2}{49.3}\)= \(\frac{441}{147}\)
Mình làm rồi nhưng bạn thử tính lại cho chắc nha
Chúc bạn học tốt!
tính giá trị biểu thức
a, 3^8 / 3^4 + 2^2 *2^3
b, 3* 4^2 -- 2 * 3^2
c, \(\frac{4^6\cdot3^4\cdot9^5}{6^{12}}\)
d, \(\frac{21^2\cdot14\cdot125}{35^36}\)
e,\(\frac{45^3\cdot20^4\cdot18^2}{180^5}\)
g, \(\frac{2^{13}+2^5}{2^{10}+2^2}\)
rut gon
\(\dfrac{21^2\cdot14\cdot125}{35^2\cdot125}\)
`@` `\text {Ans}`
`\downarrow`
\(\dfrac{21^2\cdot14\cdot125}{35^2\cdot125}\)
`=`\(\dfrac{3^2\cdot7^2\cdot2\cdot7\cdot5^2}{5^2\cdot7^2\cdot5^2}\)
`=`\(\dfrac{3^2\cdot2\cdot7\cdot5^2\cdot7^2}{5^2\cdot5^2\cdot7^2}\)
`=`\(\dfrac{3^2\cdot2\cdot7}{5^2}=\dfrac{126}{25}\)
\(\frac{x+2}{x-2}-\frac{1}{x}=\frac{2}{x^2-2x}\)
mk cần gấp mong các bạn giúp đỡ
\(ĐKXĐ:\hept{\begin{cases}x\ne0\\x\ne2\end{cases}}\)
\(\frac{x+2}{x-2}-\frac{1}{x}=\frac{2}{x^2-2x}\)\(\Leftrightarrow\frac{x\left(x+2\right)}{x\left(x-2\right)}-\frac{x-2}{x\left(x-2\right)}=\frac{2}{x\left(x-2\right)}\)
\(\Leftrightarrow\frac{x\left(x+2\right)-\left(x-2\right)}{x\left(x-2\right)}=\frac{2}{x\left(x-2\right)}\)\(\Leftrightarrow x\left(x+2\right)-\left(x-2\right)=2\)
\(\Leftrightarrow x^2+2x-x+2=2\)\(\Leftrightarrow x^2+x=0\)\(\Leftrightarrow x\left(x+1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x+1=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=-1\end{cases}}\)
So sánh với ĐKXĐ ta thấy: \(x=0\)không thoả mãn
Vậy tập nghiệm của phương trình là \(S=\left\{-1\right\}\)
Ta có: \(\frac{x+2}{x-2}-\frac{1}{x}=\frac{2}{x^2-2x}\)
\(\Leftrightarrow\frac{x.\left(x+2\right)-\left(x-2\right)}{\left(x-2\right).x}=\frac{2}{x^2-2x}\)
\(\Leftrightarrow\frac{x^2+2x-x+2}{x^2-2x}=\frac{2}{x^2-2x}\)
\(\Rightarrow x^2+x+2=2\)
\(\Leftrightarrow x^2+x=0\)
\(\Leftrightarrow x.\left(x+1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x+1=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\x=-1\end{cases}}\)
Vậy \(S=\left\{-1;0\right\}\)
\(ĐKXĐ:x\ne2;x\ne0\)
\(pt\Leftrightarrow\frac{x^2+2x-x+1}{x^2-2x}=\frac{2}{x^2-2x}\)
\(\Leftrightarrow x^2+2x-x+1=2\)
\(\Leftrightarrow x^2+x-1=0\)
\(\Delta=1^2+4.1=5\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{-1+\sqrt{5}}{2}\\x=\frac{-1-\sqrt{5}}{2}\end{cases}}\)
\(\frac{x+3}{x-2}+\frac{x+2}{x}=2\)
mk cần gấp mong các bạn giúp đỡ
Đkxđ: \(\hept{\begin{cases}x\ne2\\x\ne0\end{cases}}\)
\(\frac{x+3}{x-2}+\frac{x+2}{x}=2\)
\(\Leftrightarrow\frac{x\left(x+3\right)}{x\left(x-2\right)}+\frac{\left(x-2\right)\left(x+2\right)}{\left(x-2\right)x}=\frac{2x\left(x-2\right)}{x\left(x-2\right)}\)
\(\Rightarrow x\left(x+3\right)+\left(x-2\right)\left(x+2\right)=2x\left(x-2\right)\)
\(\Leftrightarrow x^2+3x+x^2-4=2x^2-4x\)
\(\Leftrightarrow x^2+3x+x^2-2x^2+4x=4\)
\(\Leftrightarrow7x=4\)
\(\Leftrightarrow x=\frac{4}{7}\)
Tìm x biết:
a) \(\left(x+\frac{1}{2}\right).\left(x-\frac{3}{4}\right)=0\)
b) \(\left(\frac{1}{2}.x-3\right).\left(\frac{2}{3}x+\frac{1}{2}\right)=0\)
c) \(\frac{2}{3}-\frac{1}{3}.\left(x-\frac{3}{2}\right)-\frac{1}{2}\left(2x+1\right)=5\)
d) \(4x-\left(x+\frac{1}{2}\right)=2x-\left(\frac{1}{2}-5\right)\)
MONG CÁC BN GIÚP ĐỠ MK BÀI NÀY , MK ĐANG CẦN RẤT GẤP GIẢI CHI TIẾT RA GIÚP MK VS NHÉ !!!MK RẤT CẢM ƠN!
\(\frac{x +1}{x -1}-\frac{x-1}{x+1}=\frac{x^2+3}{1-x^2}\)
mk cần gấp mong các bạn giúp đỡ
Mình thiếu điều kiện xác định ^_^
Cho mình bổ xung thêm
\(ĐKXĐ:x\ne\pm1\)
và mình sửa lại nữa là: \(\orbr{\begin{cases}x=-1\left(L\right)\\x=-3\left(TM\right)\end{cases}}\)
Vậy \(S=\left\{-3\right\}\)
\(\frac{x+1}{x-1}-\frac{x-1}{x+1}=\frac{x^2+3}{1-x^2}\) đkxđ \(x\ne\pm1\)
\(\Leftrightarrow\frac{\left(x+1\right)^2}{\left(x-1\right)\left(x+1\right)}-\frac{\left(x-1\right)^2}{\left(x+1\right)\left(x-1\right)}=\frac{-x^2-3}{\left(x+1\right)\left(x-1\right)}\)
\(\Leftrightarrow x^2+2x+1-x^2-2x-1+x^2+3=0\)
\(\Leftrightarrow x^2+3=0\)
\(\Leftrightarrow x^2=-3\)
\(\Leftrightarrow x\in\varnothing\)
\(ĐKXĐ:x\ne\pm1\)
\(pt\Leftrightarrow\frac{\left(x+1\right)^2-\left(x-1\right)^2}{x^2-1}=\frac{-x^2-3}{x^2-1}\)
\(\Leftrightarrow\left(x+1\right)^2-\left(x-1\right)^2=-x^2-3\)
\(\Leftrightarrow x^2+2x+1-x^2+2x-1=-x^2-3\)
\(\Leftrightarrow x^2+4x+3=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=-3\\x=-1\end{cases}}\)
a,-8/3+7/5+-71/15<x<-13/7+19/14+-7/2
b,-19/6+-15/2+11/3<x<-5/4+19/12+-10/3
c,-6/7+3/35<x<-2/5+3/7
d,x=3/4+1/-12
e,x/14=1/7+-3/14
f,11/18+13/6=85/x
g,8/17+5/17<x/17<6/17+9/17
mong các bn giúp đỡ mk vs mk cần rát gấp
ai nhanh giúp mk thì mk tick cho 3 tick mk thề có lòng tự trọng
ai lm nhanh mk cho 10 tick lun nhanh nha đang cần gấp
các bn lm đến đâu cx dc miễn là lm hộ mk cái ạ, ai đang lm vào nhắn tin vs mk để mk bít nha
a; \(-\dfrac{8}{3}+\dfrac{7}{5}-\dfrac{71}{15}< x< -\dfrac{13}{7}+\dfrac{19}{14}-\dfrac{7}{2}\)
-\(\dfrac{19}{15}\) - \(\dfrac{71}{15}\) < \(x\) < -\(\dfrac{1}{2}\) - \(\dfrac{7}{2}\)
-6 < \(x\) < -4
vì \(x\) \(\in\) Z nên \(x\) = -5
- \(\dfrac{19}{6}+\dfrac{-15}{2}+\dfrac{11}{3}\) < \(x\) < - \(\dfrac{5}{4}\) + \(\dfrac{19}{12}\) - \(\dfrac{10}{3}\)
- \(\dfrac{32}{3}+\dfrac{11}{3}< x< \) \(\dfrac{1}{3}\) - \(\dfrac{10}{3}\)
-7 < \(x\) < - 3
Vì \(x\in\) Z nên \(x\in\) {-6;-5;-4}
Tính giá trị biểu thức :
\(A=\frac{4^6\cdot3^4\cdot9^5}{6^{12}}\) ; \(B=\frac{21^2\cdot14\cdot125}{35^3\cdot6}\)
\(A=\frac{4^6.3^4.9^5}{6^{12}}=\frac{\left(2^2\right)^6.3^3.\left(3^2\right)^5}{6^{12}}\)
\(=\frac{2^{12}.3^3.3^{10}}{6^{12}}=3^{13}.3^{12}=3^{25}\)
\(A=\frac{4^6.3^4.9^5}{6^{12}}\)
\(A=\frac{2^6.2^6.3^4.3^5.3^5}{2^{12}.3^{12}}\)
\(A=\frac{3^3.3^5}{1}\)
\(A=3^8\)
\(B=\frac{21^2.14.125}{35^3.6}\)
\(B=\frac{3^2.7^2.2.7.5^3}{5^3.7^3.2.3}\)
\(B=\frac{3.1.1.1.1}{1.1.1.1}\)
\(B=3\)