45 x 48 - 90 x 24 + 1999 = 45 x 48 - 45 x 2 x 24 + 1999
= 45 x 48 - 45 x 48 + 1999
= 0 + 1999
= 1999
Chúc bạn hok tốt nha!
45 x 48 - 90 x 24 + 1999
= 45 x 48 - 45 x 48 + 1999
= 45 x ( 48 - 48 ) + 1999
= 45 x 0 + 1999
= 1999
\(45.48-90.24+1999\)
\(=45.48-\left(45+45\right).24+1999\)
\(45.48-45.24-45.24+1999\)
\(=0+1999\)
=1999
45 x 48 - 90 x 24 + 1999
= 45 x 48 - 45 x 48 + 1999
= 45 x ( 48 - 48 ) + 1999
= 45 x 0 + 1999
= 1999