4x - 20 = 25 : 22
=> 4x - 20 = 8
=> 4x = 8 + 20
=> 4x = 28
=> x = 28 : 4
=> x = 7
\(4x-20=2^5:2^2\)
\(4x-20=8\)
\(4x=8+20\)
\(4x=28\)
\(x=28:4\)
\(x=7\)
Câu 2:
\(9127-y:409=9^2-102\)
\(9127-y:409=-21\)
\(y:409=9127-\left(-21\right)\)
\(y:409=9148\)
\(y=9148\times409\)
\(y=3741532\)
mk nhé bạn ^...^ ^_^