18+21+23+20+19+15=( )*( )-( )=( )
18+21+23+20+19+15=( )*( )-( )=( )
17+18+19+20+21+22+23+24=( )×( )=( ) 120+130+140+150+160+170=
找规律填空.21+19=40 20+20=40 17+23=40 12+28=40 ()+()= ()+()= ()+(
11+12+13+14+15+17+18+19+20=( )*( )=( )
(-23)+16+(-15)=【?】+?27+(-19+(-27)+19=【?】+【?】=?
15,21,18,19,21,17,( ),( ).说出理由.
找规律15,21,18,19,21,17,( ),( )
15,21,18,19,21,17,( ),( )
(-10)+(-15)-(+18)-20=( )10( )15( )18(
求解(-10)+(-15)-(+18)-20=( )10( )15( )18(
(1)27+18+41= (2)19+31+8 (3)91-23-18= (4)80-15-24
19又19分之18乘以(-20)=?