a: \(\Leftrightarrow142\cdot16-7\cdot25-4x=4\cdot157\)
\(\Leftrightarrow2097-4x=628\)
=>4x=1469
hay x=1469/4
b: \(\Leftrightarrow\left[\left(7x+23\right):36-2704\right]=324\cdot29=9396\)
\(\Leftrightarrow\left(7x+23\right):36=12100\)
=>7x+23=435600
=>7x=435577
hay x=435577/7