Question

815 - 23 -77 +185

Answer 1

815-23-77+185=(815+185)-(23+77)=1000-100=900

Answer 2

\(815-23-77+185\)
\(=\left(815+185\right)-\left(77+23\right)\)
\(=1000-100\)
\(=900\)

Answer 3

900