Answer:
The lines' lengths are: 8 inches and 5 inches.
Step-by-step explanation:
Calling "a" the length of the line, a line that is 3 inches shorter can be written in math terms as:
a - 3
If the combined (added) length of these two lines is 15 inches, then we can write:
a + (a - 3) = 15
a + a - 3 = 15
2 a - 3 = 15
2 a = 15 + 3
2 a = 18
then
a = 18/2 = 9
Therefore, the length of one line is 8 inches, and the length of the shorter line is:
8 - 3 = 5 inches
