72x - 4.75 = 75.3
72x = 75.3 + 4.75
72x = 75.(3 + 4)
72x = 75.7
72x = 76
2x = 6
x = 6 : 2
x = 4
47 – 7(x + 5) = 2^5.3
47 - 7x - 35 = 32. 3
12 - 7x = 96
7x = -84
x = -12
\(47-7\left(x+5\right)=2^5.3\)
\(47-7\left(x+5\right)=32.3\)
\(47-7\left(x+5\right)=96\)
\(-7\left(x+5\right)=47-96\)
\(-7\left(x+5\right)=-49\)
\(x+5=\left(-49\right):\left(-7\right)\)
\(x+5=7\)
\(x=7-5\)
\(x=2\)
Vậy \(x=2\)