Question

what is the combined land area of the countries A and B is 154,973 square kilometers. Country A is larger by 573 square kilometers. Determine the land area of each country

Answer 1

Start with B=A-573. --> A+B=154,973.--> A+(A-573)=154,973. --> 2A-573=154,973. --> 2A = 154,400. --> A = 154,400/2 = 77,200. A= 77,200. 
To find B. :: 77,200+B=154,973. Subtract A from combined area.--> B = 77,773