2.25×0.16+264×0.0225+5.2×2.25+0.225×20
=2.25×0.16+2.25x2.64+5.2×2.25+2.25×2
=2.25x(0.16+2.64+5.2+2)
=2.25x(2.8+5.2+2)
=2.25x10
=22.5