14\([\) (8x-12):4\(]\) .36 =39
14.\([\)(8x-12):4\(]\) =33
(8x-12):4=\(\dfrac{27}{14}\)
8x-12=\(\dfrac{27}{14}\).4
8x=\(\dfrac{54}{7}\) +12
8x=\(\dfrac{138}{7}\)
x=\(\dfrac{138}{56}\)
khum bt đúng khum
16)213-(x-6)=1236:12
<=>213-(x-6)=103
<=>x-6=213-103
<=>x-6=110
<=>x=116
17)3(2x-1)3+1=5.16
<=>3(2x-1)3+1=80
<=>3(2x-1)3 =81
<=>(2x-1)3 =27
<=>2x-1=3
<=>2x=4
=>x=2
13) Ta có: \(x+\left(-36\right)=33-\left|-103\right|\)
\(\Leftrightarrow x-36=33+103\)
\(\Leftrightarrow x=172\)
14) Ta có: \(\left[\left(8x-12\right):4\right]\cdot3^6=3^9\)
\(\Leftrightarrow\left(8x-12\right):4=3^3=27\)
\(\Leftrightarrow8x-12=108\)
\(\Leftrightarrow8x=120\)
hay x=15
15) Ta có: \(220+\left[2^4+\left(x-5\right)\right]=8^2\cdot5\)
\(\Leftrightarrow220+16+x-5=64\cdot5=320\)
\(\Leftrightarrow x+231=320\)
hay x=89
16) Ta có: \(213-\left(x-6\right)=1236:12\)
\(\Leftrightarrow213-\left(x-6\right)=103\)
\(\Leftrightarrow x-6=213-103=110\)
hay x=116
17) Ta có: \(3\left(2x-1\right)^3-1^{2020}=5\cdot4^2\)
\(\Leftrightarrow3\cdot\left(2x-1\right)^3=5\cdot16+1=81\)
\(\Leftrightarrow2x-1=3\)
hay x=2