4c(2x+3) is my question. how to answer?

Jason went to an arcade to play video games. he paid $2 for every 11 tokens he bought. he spent a total of $16 on tokens. which equation can be used to determine,t, the number lf tokens jason bought

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.

Given that sin∅ = 1/4, 0 < ∅ < π/2, what is the exact value of cos∅? a. (√4)/4 b. (√15)/4 c. (4π)/2 d. (4√2)/4