Answer:
Step-by-step explanation:
In equation form,
children + adults = 48 people at the library.
If the number of children is 3 times the number of adults, then in equation form:
children = adults*3
Let's call children c and adults a. Subbing the second equation into the first gives us an equation with only one unknown instead of 2.
c + a = 48 after making the substitution is
3a + a = 48 and
4a = 48 so
a = 12
There were 12 adults. If the total number of people was 48, then
48 - 12 = number of children so
c = 36
