a) \(45:\left(3x-19\right)=3^2\)
\(3x-19=45:9\)
\(3x=5+19\)
\(x=\frac{24}{3}\)
\(x=8\)
vậy \(x=8\)
b) \(57+7.64-x:3^2=500\)
\(448-x:9=500-57\)
\(448-x:9=443\)
\(x:9=448-443\)
\(x:9=5\)
\(x=45\)
vậy \(x=45\)
c) \(2^3.2^x=128\)
\(2^{x+3}=2^7\)
\(\Rightarrow x+3=7\)
\(\Rightarrow x=4\)
vậy \(x=4\)
a. 45:(3x-19)=3^2
45:(3x-19)=9
3x-19=45:9
3x-19=5
3x =5+19
3x =24
x =24:3
x =8
mấy câu còn lại mình chịu
a, 45 : (3x-19)= 9
3x-19= 5
3x=24
x=8
b, 57+7.64-x:9=500
57+448-x:9=500
505-x:9=500
5=x:9
x=\(\frac{5}{9}\)