a 47.52+47.49-47 = 47 . ( 52+49-1) = 47.100 = 4700
b [780-5.(3³+5.2²)]+4²
=[780-5.(27+5.4)]+16=[780-5.47]+16=[780-235]+16=545+16=561
c 168:{46-[12+5.(32:16)]}=168:{46-[12+5.2]}=168:{46-22}=168:24=7
2
a)2x-36=4mũ6:4³
2x-36=4^3
2x = 64+36
2x =100
x =100 : 2
x =50
b)x-87:29=3
x-3=3
x=3+3
x=6