Ta thấy:
\(70-5\left(x-3\right)=40\)
\(\Rightarrow5\left(x-3\right)=70-40\)
\(\Rightarrow5\left(x-3\right)=30\)
\(\Rightarrow x-3=30\div5\)
\(\Rightarrow x-3=6\)
\(\Rightarrow x=6+3\)
\(\Rightarrow x=9\)
70 - 5 ( x - 3 ) = 40
5 ( x - 3 ) = 70 - 40
5 ( x - 3 ) = 30
x - 3 = 30 :5
x - 3 = 6
x = 6+ 3
x = 9
x=65(x-3)=40
x= x-(65-3) =40
x-62=40
x=40+62
x=102
70 - 5 ( x - 3 ) = 40
5 ( x - 3 ) = 70 - 40
5 ( x - 3 ) = 30
x - 3 = 30 : 5
x - 3 = 6
x = 6 + 3
x = 9