Hi Im Jenny Im here to help you with your math problem and I am totally for you dealing with brainly deleting question because they do that a lot with me. Its kind of weird that they think you have a calculator and you want to use brainly you know! Aren't they supposed to promote their site?
Here,
8x9x4x5
Lets break this problem down! :)
8x9
72
x4
288
x5
1440
Hope I helped! :)