Use the substitution method
f(x)= 3-2x
f(4)= 3-2(4)
Do multiply first then subtract
= 3-8
= -5
Answer : f(4)= -5
Number of wars two numbers can be formed with repetition allowed = 10^2 = 100 ways.
Number of ways 3 letters can be formed with repetition allowed = 26^3 = 17,567
Therefore, Number of license plates that can be made with 2 numbers followed by 3 letters with repitition allowed = 100 x 17,567 = 1,757,600
option a is the correct answer.
Depends on the question...
If your question is 2/3b + 5 = 7, then follow this one

Your final answer will be b = 3
If your question is 2/3b - 5 = 7, then follow this one

Your final answer will be b = 18
The answer is 3 1/2 inches bro hope this helpes you