Tìm x:
a)1/9 . 3/4 . 3^x = 3^7
b) 3^x + 1 = 9^x
Làm ơn giúp mik càng nhanh càng tốt ạ
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\frac{22}{9}-\left(x+\frac{1}{2}\right)^2=\frac{7}{3}\)
\(\left(x+\frac{1}{2}\right)^2=\frac{22}{9}-\frac{7}{3}\)
\(\left(x+\frac{1}{2}\right)^2=\frac{1}{9}\)
\(\left(x+\frac{1}{2}\right)^2=\left(\frac{1}{3}\right)^2\)
\(\Rightarrow x+\frac{1}{2}=\frac{1}{3}\)
\(x=\frac{1}{3}-\frac{1}{2}\)
\(x=-\frac{1}{6}\)
\(\frac{22}{9}-\left(x+\frac{1}{2}\right)^2=\frac{7}{3}\)
\(\left(x+\frac{1}{2}\right)^2=\frac{22}{9}=\frac{7}{3}\)\
\(\left(x+\frac{1}{2}\right)^2=\frac{22}{9}-\frac{21}{9}\)
\(\left(x+\frac{1}{2}\right)^2=\frac{1}{9}\)
\(\Rightarrow x+\frac{1}{2}=\pm\frac{1}{3}\)
TH1:\(x+\frac{1}{2}=\frac{1}{3}\)
\(x=\frac{1}{3}-\frac{1}{2}\)
\(x=-\frac{1}{6}\)
TH2:\(x+\frac{1}{2}=-\frac{1}{3}\)
\(x=-\frac{1}{3}-\frac{1}{2}\)
\(x=-\frac{5}{6}\)
Vậy \(x\in\left\{-\frac{1}{6};-\frac{5}{6}\right\}\)
= x3 + 33 -x(x2 -1) -27 =0 ( tổng các lập phuong)
x =0
CX100%
A.\(\left(\frac{4}{7}.x-1\right).3=\frac{1}{21}\)
\(\frac{4}{7}.x-1=\frac{1}{21}:3\)
\(\frac{4}{7}.x-1=\frac{1}{21}.3\)
\(\frac{4}{7}.x-1=\frac{1}{7}\)
\(\frac{4}{7}.x=1+\frac{1}{7}\)
\(\frac{4}{7}.x=\frac{8}{7}\)
\(x=\frac{8}{7}:\frac{4}{7}\)
\(x=\frac{8}{7}.\frac{7}{4}\)
\(x=2\)
Vậy x=2
C.\(\frac{2}{3}.x-\frac{1}{3}.x=\frac{5}{9}\)
\(\left(\frac{2}{3}-\frac{1}{3}\right).x=\frac{5}{9}\)
\(\frac{1}{3}.x=\frac{5}{9}\)
\(x=\frac{5}{9}:\frac{1}{3}\)
\(x=\frac{5}{9}.3\)
\(x=\frac{5}{3}\)
Vậy \(x=\frac{5}{3}\)
D. \(\left(x-2\frac{1}{4}\right).\left(\frac{-2}{3}\right).50\%=2\frac{5}{6}\)
\(x.\frac{-2}{3}-\frac{9}{4}.\frac{-2}{3}=\frac{17}{6}:\frac{1}{2}\)
\(x.\frac{-2}{3}-\frac{-3}{2}=\frac{17}{6}.2\)
\(x.\frac{-2}{3}+\frac{3}{2}=\frac{17}{3}\)
\(x.\frac{-2}{3}=\frac{17}{3}-\frac{3}{2}\)
\(x.\frac{-2}{3}=\frac{34}{6}-\frac{9}{6}\)
\(x.\frac{-2}{3}=\frac{25}{6}\)
\(x=\frac{25}{6}:\frac{-2}{3}\)
\(x=\frac{25}{6}.\frac{3}{-2}\)
\(x=\frac{25}{-4}\)
Vậy \(x=\frac{25}{-4}\)
a) \(\left(7-14x\right)\left(x-2\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}7-14x=0\\x-2=0\end{cases}\Leftrightarrow\orbr{\begin{cases}14x=7-0\\x=2\end{cases}\Leftrightarrow}}\orbr{\begin{cases}14x=7\\x=2\end{cases}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=2\end{cases}}}\)
Vậy \(x\in\left\{\frac{1}{2};2\right\}\)
b) \(\left(2x+1\right)\left(x-3\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}2x+1=0\\x-3=0\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=-1\\x=3\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\frac{-1}{2}\\x=3\end{cases}}}\)
Vậy \(x\in\left\{-\frac{1}{2};3\right\}\)
Bài làm
a, x - 3 = -6 b, x-(-5) = 4 c, x - ( -9 ) = 4 - ( -9 ) d, 4 - x = -3 - ( -6 )
x = -6 + 3 x + 5 = 4 x + 9 = 4 + 9 4 - x = 3
x = -3 x = 4 - 5 x + 9 = 13 x = 4 - 3
Vậy x = -3 x = 9 x = 13 - 9 x = 1
Vậy x = 9 x = 4 Vậy x = 1 Vậy x = 4
# Chúc bạn học tốt #
\(\left(x-3\right)\left(x^2+3x+9\right)+x\left(x+2\right)\left(2-x\right)=1\)
\(x^3-3^3+x\left(2^2-x^2\right)=1\)
\(x^3-27+4x-x^3=1\)
\(4x-27=1\)
\(4x=28\)
\(x=7\)
Vậy x = 7
Bài 1:
a,x=11
b,không tồn tại giá trị của x
c,x=-3
Bài 2:
a,=300
b,=51
a: \(\Leftrightarrow3^{x+4}=3^7:\dfrac{1}{9}=3^9\)
=>x+4=9
hay x=5
b: \(\Leftrightarrow3^{x+1}=3^{2x}\)
=>2x=x+1
hay x=1