64/4+3*9*7-91/(28/4)=192 28/4=7 3*7*9=189 64/4=16 91/7=13 16+189-13=192 (69*2-6*8)/5+170*3/10=69 69*2=138 6*8=48 138-48=90 170*3=510 510/10=51 90/5=18 18+51=69