-5 - (24 - x ) = 12 + (42-65)
\(\Leftrightarrow\) -5-24-x = 12+42-65
\(\Leftrightarrow\) x - 29 = -11
\(\Leftrightarrow\) x = -11+29
\(\Leftrightarrow\) x = 18
a,-5 - (24 - x ) = 12+(42-65 )
-> -5 - (24-x) = 12+ ( -23)
-> -5 - (24-x) = -11
-> - (24-x) = -11 - 5
->- (24-x) = -16
->24-x = 16
-> x = 18
Vậy x = 18
-5 - (24 - x ) = 12+(42-65 )
-> -5 - (24-x) = 12+ ( -23)
-> -5 - (24-x) = -11
-> - (24-x) = -11 - 5
->- (24-x) = -16
->24-x = 16
-> x = 18
Cách 1:Dùng quy tắc chuyển vế
\(-5-\left(24-x\right)=12+\left(42-65\right)\)
\(-5-\left(24-x\right)=12+\left(-23\right)\)
\(-5-\left(24-x\right)=-11\)
\(-\left(24-x\right)=-11+5\)
\(-\left(24-x\right)=-6\)
\(24-x=6\)
\(x=24-6\)
\(x=18\)
Vậy \(x=18\)
Cách 2:Tính thông thường
\(-5-\left(24-x\right)=12+\left(42-65\right)\)
\(-5-\left(24-x\right)=12+\left(-23\right)\)
\(-5-\left(24-x\right)=-11\)
\(24-x=-5-\left(-11\right)\)
\(24-x=6\)
\(x=24-6\)
\(x=18\)
Vậy \(x=18\)