a)\(2^2.3\)
\(=4.3\)
\(=12\)
b)\(9^{20}:9^{18}-\left(4^2-7\right)^2+8.5^2+5600:\left(3^3+1^8\right)\)
\(=9^2-\left(16-7\right)^2+8.25+5600:\left(27+1\right)\)
\(=9^2-9^2+200+5600:28\)
\(=9^2-9^2+200+200\)
\(=0+200+200\)
\(=400\)
_Chúc bn học tốt nhé!_