-72 - ( 15 - x ) = -43 - (-13)
-72 - 15 + x = -43 + 13
x = -43 + 13 + 72 + 15
x = -30 + 87
x = 57
-72 - ( 15 - x ) = -43 - (-13)
-72 - 15 + x = -43 + 13
x = -43 + 13 + 72 + 15
x = -30 + 87
x = 57
- 72 - ( 15 - x ) = - 43 - ( -13 )
\(\Rightarrow\) - 72 - 15 + x = - 43 + 13
\(\Rightarrow\) - 87 + x = - 30
\(\Rightarrow\) x = 57
Study well ! >_<
\(-72-(15-x)=-43-(-13)\)
\(-72-(15-x)=-30\)
\(15-x=-72+30\)
\(15-x=-42\)
\(x=15+42\)
\(x = 57 \)