(12:3+4)·5=40
1·(-2-3+45)=40
(1-2+3)·4·5=40
1-2·3+45= 40
(-1+2+3+4)·5=40
(12:3)·4·5=80
-(1-2-3)·4·5=80
(-1+2+3)·4·5=80
1+ (-2)+3(4*5)=40 -1+2+3(4*5)=80
