Draw straight lines down your graph and if the line passes two lines on the graph then it’s not a function but if the line you draw a line and it only hits one line on the graph and doesn’t cross another then it’s a function. A and b are not functions because they fail the vertical line test c however passes the vertical line test meaning it’s a function
Terms in a math problem:
3a, -7, 4, 2x^4
A = 8 C = 8
AC = C-A = 8-0 = 8
C=8 F = 20
CF = F-C = 20-8 = 12
so the ratio would be 8/12 which reduces to 2/3
answer is D