1/4+1/3:(2xX+1)=-5
1/4+1/3:(2xX+1)=-5
1/4+1/3:(2×X+1)=-5
7/12:(2×X+1)=-5
2×X+1=-5×7/12
2×X+1=-35/12
2×X=-35/12-1
2×X=-47/12
X=-47/12:2
X=47/24
Vậy X bằng 47/24
Chúc bạn học tốt
Tìm X:
a,2xX-5=21
b,3/4+1/4xX=5/6
c,7/8-1/2xX=5/6
d(1/1x2+1/2x3+1/3x4)x100-[5/2:(X+206/100)]:1/2=89
\(a)\) \(2x-5=21\)
\(\Leftrightarrow\) \(2x=21+5\)
\(\Leftrightarrow\) \(2x=26\)
\(\Leftrightarrow\) \(x=26:2\)
\(\Leftrightarrow\) \(=13\)
\(b)\) \(\frac{3}{4}+\frac{1}{4}x=\frac{5}{6}\)
\(\Leftrightarrow\) \(\frac{1}{4}x=\frac{5}{6}-\frac{3}{4}\)
\(\Leftrightarrow\) \(\frac{1}{4}x=\frac{1}{12}\)
\(\Leftrightarrow\) \(x=\frac{1}{3}\)
\(c)\) \(\frac{7}{8}-\frac{1}{2}x=\frac{5}{6}\)
\(\Leftrightarrow\) \(\frac{1}{2}x=\frac{7}{8}-\frac{5}{6}\)
\(\Leftrightarrow\) \(\frac{1}{2}x=\frac{1}{24}\)
\(\Leftrightarrow\) \(x=\frac{1}{12}\)
5/4:X-3/2=3/2+1/2xX
\(\dfrac{5}{4x}-\dfrac{3}{2}=\dfrac{3}{2}+\dfrac{x}{2}\\ \Leftrightarrow5-6x=6x+2x^2\\ \Leftrightarrow2x^2+12x-5=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-6+\sqrt{46}}{2}\\x=\dfrac{-6-\sqrt{46}}{2}\end{matrix}\right.\)
tìm x:
a,2/3xX+1/4=5/6
b,7/12-5/6xX=1/4:2/3
c,2 và 1/3-(x+1)= 5/9
d, 2xX+1 trên 15=3/5
a)\(\frac{2}{3}\cdot x+\frac{1}{4}=\frac{5}{6}\)
\(\frac{2}{3}\cdot x=\frac{5}{6}-\frac{1}{4}=\frac{7}{12}\)
\(x=\frac{7}{12}:\frac{2}{3}=\frac{7}{8}\)
b) \(\frac{7}{12}-\frac{5}{6}\cdot x=\frac{1}{4}:\frac{2}{3}\)
\(\frac{7}{12}-\frac{5}{6}\cdot x=\frac{3}{8}\)
\(\frac{5}{6}\cdot x=\frac{7}{12}-\frac{3}{8}=\frac{5}{24}\)
\(x=\frac{5}{24}:\frac{5}{6}=\frac{1}{4}\)
c) \(2\frac{1}{3}-\left(x+1\right)=\frac{5}{9}\)
\(\frac{7}{3}-\left(x+1\right)=\frac{5}{9}\)
\(x+1=\frac{7}{3}-\frac{5}{9}=\frac{16}{9}\)
\(x=\frac{16}{9}-1=\frac{7}{9}\)
d) \(\frac{2\cdot x+1}{15}=\frac{3}{5}\)
\(\left(2\cdot x+1\right):15=\frac{3}{5}\)
\(2\cdot x+1=\frac{3}{5}\cdot15=9\)
\(2\cdot x=9-1=8\)
\(x=8:2=4\)
a, 2/3 . x +1/4=5/6
2/3 . x=5/6-1/4
2/3 . x=10/12 -3/12
2/3 . x=7/12
x= 7/12 : 2/3
x=7/8
Vậy x=7/8
b)0,5xx+2/3xx+2/3=7/12
c)3/5-2/15:x=1/2
d)50%xx-2va1/2=2va5/6
e)(2va4/5xx-50):2/3-51
f)(4va1/2-2xx)x3va2/3=11/15
g)02/5-(2va1/2xx-3):15=1/10
h)(3/4+x)x1/1+5va1/6-1va1/6
b)0,5xx+2/3xx+2/3=7/12
c)3/5-2/15:x=1/2
d)50%xx-2va1/2=2va5/6
e)(2va4/5xx-50):2/3-51
f)(4va1/2-2xx)x3va2/3=11/15
g)02/5-(2va1/2xx-3):15=1/10
h)(3/4+x)x1/1+5va1/6-1va1/6
Thực hiện phép trừ 2 x x - 1 - x x - 1 - 1 x - 1 . Cách thực hiện nào sau đây là sai ?
A. 2 x x - 1 - x x - 1 - 1 x - 1 = 2 x x - 1 - x x - 1 - 1 x - 1 = . . .
B. 2 x x - 1 - x x - 1 - 1 x - 1 = 2 x x - 1 - x x - 1 - 1 x - 1 = . . .
C. 2 x x - 1 - x x - 1 - 1 x - 1 = 2 x x - 1 - x x - 1 + 1 x - 1 = . . .
D. 2 x x - 1 - x x - 1 - 1 x - 1 = 2 x x - 1 - - x x - 1 + - 1 x - 1 = . . .
1/2xX+3/4-11/2=2
X:1/4+Xx8=96
Giải các hệ phương trình sau:
a ) x 5 − ( 1 + 3 ) y = 1 ( 1 − 3 ) x + y 5 = 1 b ) 2 x x + 1 + y y + 1 = 2 x x + 1 + 3 y y + 1 = − 1
Từ (1) rút ra được: (*)
Thay (*) vào phương trình (2) ta được:
Thay vào (*) ta được:
Vậy hệ phương trình có nghiệm
b) Điều kiện xác định: x ≠ -1; y ≠ -1.
Đặt , hệ phương trình trở thành:
Vậy hệ phương trình có nghiệm a