Let:
x = Chemistry textbooks sold
y = Physics textbooks sold
The textbook store sold a combined total of 260, so:
The number of chemistry books sold was three times the number of physics textbooks sold, so:
Let:
Replace (2) into (1):
Replace the value of y into (2):
The length of UC is 18
<h2>Explanation </h2>First we are going to find the length of JN; then we are subtracting from it the length of JU plus the length of CN.
We can infer from our picture that JN is 82 + 105, so JN = 187
We can also infer that JU = JH + HU
JU = 22 + 96
JU = 118
We can also infer that CN = 51
Now we can fin the length of UC:
We can conclude that the length of UC is 18.