15▪3+(8▪13-5▪3)
=15×3-5×3+8×(10+3)
=3×(15-5)+8×10+8×3
=30+80+24
=110+24
=134
56▪25-(16▪4-3▪75)
=56×25+3×3×25-16×4
=25×(56+9)-64
=25×65-65+1
=65×(25-1)+1
=65×24+1
=1560+1
=1561
15▪3+(8▪13-5▪3)
=15.3-5.3+8.13
=10+8.13
=18.13
56▪25-(16▪4-3▪75)
=56.25+3.75-16.4
=60-16.4
=43.6