find each function value.
1). f(1)if f(x) = x+ 3
2). f (6) if f(x) =2x
3). f(4) if f(x) =5x-4
need help with all 3 questions step by step
1). f(1)if f(x) = x+ 3
2). f (6) if f(x) =2x
3). f(4) if f(x) =5x-4
need help with all 3 questions step by step