a) 4x7+4x11+4x22
=28+44+88
=72+88
=160
5x30+5x25+5x15
=150+125+75
=275+75
=350
b) 9x50-9x35-9x12
=450-315-108
=135-108
=27
7x45-7x32-7x7
=315-224-49
=91-49
=42
pup
