(x+1/4)2=1/64
giup mik vs
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(x+\frac{1}{4}=\frac{1}{64}\)
\(x=\frac{1}{64}-\frac{1}{4}\)
\(x=-\frac{15}{64}\)
Vậy x = -15/64
hok tốt
==.==
1.
a) \(2^x=128\)
\(2^x=2^7\)
\(=>x=7\)
b) \(8^{x-1}=64\)
\(8^{x-1}=8^2\)
\(=>x-1=2\)
\(x=2+1\)
\(=>x=3\)
c) \(3+3^x=30\)
\(3^x=30-3\)
\(3^x=27=3^3\)
\(=>x=3\)
d) \(\left(x+2\right)=64\) -> đề có thiếu không vậy?
e) \(3^2.x=3^5\)
\(x=3^5:3^2\)
\(=>x=3^3=27\)
f) \(\left(2x-1\right)^3=343\)
\(\left(2x-1\right)^3=7^3\)
\(=>2x-1=7\)
\(2x=7+1\)
\(2x=8\)
\(x=8:2\)
\(=>x=4\)
\(#Wendy.Dang\)
a,\(2^x\)=128 b,\(8^{x-1}\)=64 c,3+\(3^x\)=30 d,x+2=64
\(2^7\)=128 \(8^{x-1}\)=\(8^2\) \(3^x\)=30-3 x=64-2
=>x=7 =>x-1=2 \(3^x\)=27 x=62
x=2+1=3 \(3^x\)=\(3^3\)
=>x=3
e,\(3^2\).x=\(3^5\) f,(2x-\(1^3\))=343
x=\(3^5\):\(3^2\) 2x=1+343
x=27 2x=344
x=344:2
x=172
\(3\left(x-1\right)^2-x^2+1=0\)
\(\Leftrightarrow3\left(x-1\right)^2-\left(x^2-1\right)=0\)
\(\Leftrightarrow3\left(x-1\right)^2-\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left[3\left(x-1\right)-\left(x+1\right)\right]=0\)
\(\Leftrightarrow\left(x-1\right)\left(3x-3-x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(2x-4\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-1=0\\2x-4=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=1\\2x=4\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=1\\x=2\end{cases}}}\)
(x-1).(y+2)=5
\(\Rightarrow\)x-1 và y+2 \(\in\)B(5)
\(\Rightarrow\)B(5)\(\in\)\(\left\{\pm1;\pm5\right\}\)
\(\Rightarrow\)Ta có bảng sau:
x-1 | -1 | 1 | -5 | 5 |
---|---|---|---|---|
x | 0 | 2 | -4 | 6 |
y+2 | -5 | 5 | -1 | 1 |
y | -7 | 3 | -3 | -1 |
Vậy:............
nhớ k cho mk!!!
Chúc bạn học tốt
(x-1).(y+2)=5
=>x-1;y+2\(\inƯ\left(5\right);x,y\in Z\)
Khi đó ta có bảng sau
X-1 | -1 | -5 | 1 | 5 |
X | 0 | -4 | 2 | 6 |
Y+2 | -5 | -1 | 5 | 1 |
Y | -7 | -3 | 3 | -1 |
Vậy (x;y) \(\in\){(0;-7),(-4;-3),(2;3),(6;-1)}
(x+1/4)^2=(1/8)^2
=>x+1/4=1/8
=> x=1/8-1/4
=> x=-1/8
\(\left(x-\frac{1}{4}\right)^2=\frac{1}{64}\)
\(\Leftrightarrow\left(x-\frac{1}{4}\right)^2=\left(\frac{1}{8}\right)^2\)
\(\Leftrightarrow x-\frac{1}{4}=\frac{1}{8}\)
\(\Leftrightarrow x=\frac{1}{8}+\frac{1}{4}\)
\(\Leftrightarrow x=\frac{1}{8}+\frac{2}{8}\)
\(\Leftrightarrow x=\frac{3}{8}\)
Vậy \(x=\frac{3}{8}\)