Step 1: Interpret the statement provided in the question using mathematics equation
Let the area of town A be x
Let the area of town B be y
Therefore, since the sum of the two areas is 140000 sq miles, then,
[tex]x+y=140000-----1[/tex]Step 2: From the second statement, the area of town A (x) is 10000 sq miles more than the area of town B (y), thus, this implies
[tex]x=y+10000-----2[/tex]Step 3: Substitute the value of x in equation 2 into equation 1 to find the value of y
[tex]\begin{gathered} \text{If }x=y+10000, \\ x+y=140000\text{ will be} \\ (y+10000)+y=140000 \end{gathered}[/tex]Step 4: Collect like terms and solve for y
[tex]\begin{gathered} y+y=140000-10000 \\ 2y=130000 \end{gathered}[/tex]Divide both sides by the coefficient of y, which is 2
[tex]\begin{gathered} \frac{2y}{2}=\frac{130000}{2} \\ y=65000\text{ sq. miles} \end{gathered}[/tex]Step 5: Substitute the value of y = 65000 in equation 2 to find x
[tex]\begin{gathered} x=y+10000 \\ x=65000+10000 \\ x=75000\text{ sq miles} \end{gathered}[/tex]Hence, the area of town A is 75000 square miles, and the area of town B is 65000 square miles.