815 - 23 - 77 + 85
= 815 + 85 - 23 - 77
= ( 815 + 85 ) - ( 23 + 77 )
= 900 - 100
= 800
\(815-23-77+85\)
\(=\left(815+85\right)-\left(23+77\right)\)
\(=900-100=800\)
815-23-77+85
=815+85-(23+77)
=900-100
=800
mình nha
815 - 23 - 77 + 85
= ( 815 - 85 ) - ( 77 + 23 )
= 730 - 100
= 630