Value of f(4) is
given 
Step-by-step explanation:
We are given
and we need to find value of f(4)
Solving:
We will put x=4 and solve the given equation:


We know (4)^2=16


So, Value of f(4) is
given 
Keywords: Solving Equations
Learn more about Solving Equations at:
#learnwithBrainly
Answer:
Let the Dulcina's collection be 'x'
Let the Tremaine collection be 'x-39'
x + x - 39 =129
2x = 129 +39
2x = 168
x = 168/2
x = 84
Dulcina's collection = x = 84
Tremaine's collection = x - 39 = 84 - 39 = 45
Answer: 72
<u>Step-by-step explanation:</u>
There are 9 students to choose from to go the library. After that person is chosen there are 8 students remaining.
First student and Second student
9 x 8 = 72