`5xx8:4-9-1xx5+345`
`=40:4-9-5+345`
`=10-9-5+345`
`=1+345-9-5`
`=346-9-5`
`=337-5`
`=332`
5 x 8 : 4 -9 - 1 x 5 + 345
= 40 : 4 - 9 - 5 + 345
= 10 - 9 - 5 + 345
= 345 - 5 + 1
= 339
5*8:4-9-1*5+345=40:4-9-1*5+345
=10-9-1*5+345
=1-1*5+345
=0*5+345
=0+345
=345