\(a,12-2:\left(x+3\right)=9\)
\(\Leftrightarrow2:\left(x+3\right)=3\)
\(\Leftrightarrow x+3=\frac{2}{3}\)
\(\Leftrightarrow x=\frac{-7}{3}\)
12-2:(x+3)=9
=> 12 - 2x - 6 = 9
=> -2x = 9+6-12 = 3
=> x= -1,5
12xy - 50 = 7xy
=> 12xy -7xy= 50
=> 5xy=50
=> xy = 10
=> x = 10/y
\(b,12y-50=7y\)
\(\Leftrightarrow12y-7y=50\)
\(\Leftrightarrow5y=50\)
\(\Leftrightarrow y=10\)
12-2:(x+3)=9 yx17-50=yx12
2:(x+3)=12-9=3 yx17-yx12=50
x+3=2:3=2/3 yx(17-12)=50
x=2/3-3=-7/3 yx5=50
y=50:5=10
tk cho mih nhé