Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
A. [( 6x - 39 ) : 7] x4=12
[(6x-39):7]=12:4
(6x-39):7=3
6x-39=3x7
6x-39=21
B. ( 2x -6 )^ 3 = 8
6x=21+39
6x=60
x=60:6
x=10
B. ( 2x -6 )^ 3 = 8
A. [ ( 6x - 39 ) : 7] x 4= 12
[ ( 6x - 39 ) : 7] = 12:4
( 6x - 39 ) : 7 = 3
6x - 39 = 3x7
6x - 39 = 21
6x = 21+39
6x = 60
x = 60:6
x = 10
Vậy x=10
B. ( 2x -6 )3 = 8
23x3-63 = 8
8 x3 - 216 = 8
8 x3 = 8+216
8 x3 = 224
x3 = 224 : 8
x3 = 28
=> x3=28
a: \(=3\cdot\left(\dfrac{1}{4}-\dfrac{6}{7}+\dfrac{8}{21}\right)\)
\(=3\cdot\left(\dfrac{21}{84}-\dfrac{72}{84}+\dfrac{32}{84}\right)\)
\(=\dfrac{-19}{28}\)
b: \(=\dfrac{-2}{3}\left(\dfrac{1}{9}-\dfrac{1}{6}-\dfrac{1}{11}\right)\)
\(=\dfrac{-2}{3}\cdot\dfrac{-29}{198}=\dfrac{29}{99\cdot3}=\dfrac{29}{297}\)
c: \(=\dfrac{-3}{7}+\dfrac{4}{25}+\dfrac{5}{16}+\dfrac{3}{16}\)
\(=\dfrac{-75+28}{175}+\dfrac{1}{2}\)
\(=\dfrac{-47}{175}+\dfrac{1}{2}=\dfrac{-94+175}{350}=\dfrac{81}{350}\)
d: \(=\dfrac{-4}{9}\cdot\left(\dfrac{1}{26}-\dfrac{1}{2}-\dfrac{1}{8}\right)\)
\(=\dfrac{-4}{9}\cdot\dfrac{-61}{104}=\dfrac{61}{26\cdot9}=\dfrac{61}{234}\)
18 - 4\(x\) = -20 - 6\(x\)
-4\(x\) + 6\(x\) = - 20 - 18
2\(x\) = - 38
\(x\) = - 19
h, -15 \(\times\) 24 = -7\(x\) + 32
7\(x\) = 360 + 32
7\(x\) = 392
\(x\) = 392:7
\(x\) = 56
i, 15\(x\) -3.(4\(x\) - 6) = -12 + 36
15\(x\) - 12\(x\) + 18 = 24
3\(x\) = 24 - 18
3\(x\) = 6
\(x\) = 2
k, -10\(x\) - 27 = -7\(x\) + 33
-27 - 33 = -7\(x\) + 10\(x\)
3\(x\) = -60
\(x\) = -20
1 Tính nhanh
a) \(-14+12+\left(-12\right)\left(2^3-7\right)\)
\(=-14+\left[12+\left(-12\right)\right].1\)
\(=-14+0.1\)
\(=-14+0=-14\)
b) \(\left(-5\right)+2\left(-15\right)-\left(-3\right)+\left|-10\right|\)
\(=\left(-5\right)+\left(-30\right)-\left(-3\right)+10\)
\(=\left(-35\right)-\left(-3\right)+10\)
\(=\left(-32\right)+10\)
\(=-22\)
c) \(68.\left(12+32\right)-32.\left(68-12\right)\)
\(=68.44-32.56\)
\(=2992-1792\)
\(=1200\)
d) \(89-\left(-43\right)-32\)
\(=132-32\)
\(=100\)
e) \(-12.\left(-6\right)^2+\left(-4\right)^3.12\)
\(=-12.36+64.12\)
\(=\left(-12+12\right).\left(36+64\right)\)
\(=0+100\)
\(=100\)
a)13-2(x+1)=7
2.(x+1)=13-7
2.(x+1)=6
x+1=6/2
x+1=3
x=3-1
x=2
a, 13 - 2 ( x + 1 ) = 7
2 .( x + 1 ) = 13 - 7
2 .( x + 1 ) = 6
x + 1 = 6 : 2
x + 1 = 3
x = 3 - 1
x = 4
[(6x-12)÷3]\(\times\)36=6
\(\Leftrightarrow\)[(6x-12)÷3]=1/6
\(\Leftrightarrow\)(6x-12)÷3=1/6
\(\Leftrightarrow\)6x-12=1/2
\(\Leftrightarrow\)6x=25/2
\(\Leftrightarrow\)x=25/12