Question

Thực hiện phép tính một cách hợp lí :

a,123.456+123.789-1245.23

b,2^9:16^2+81^5:3^18-125^7:625^5

Answer 1

123.456+123.789-1245.23

=123.(456+789)-1245.23

=123.1245-1245.23

=1245.(123-23)

=1245.100

=124500

Answer 2

=123.(456+789)-1245.23

=123.1245-1245.23

=1245.(123-23)

=1245.100

=124500

Answer 3

a)(bạn kia làm rồi)

b)2^9:16^2+81^5:3^18-125^7:625^5

=2^9:(2^4)^2+(3^4)^5:3^18-(5^3)^7:(5^4)^5

=2^9:2^8+3^20:3^18-5^21:5^20

=2+3^2+5

=2+9+5

=16