Question

Let y=f(x) be the function for which f(1) =14 f(2) =12f(5)=6andf(8)= 21 then (7)

Answer 1

Answer:

Step-by-step explanation:

Let, f(x)=ax+b

Put x=1, f(1)=a(1)+b

Therefore, -1=a+b (eqn1)

Put x=2, f(2)=2a+b

Therefore, 14=2a+b (eqn2)

Solve eqn 1 &2 simultaneously,

a=15, b=-16

which implies, f(x)=15x-16

Now, f(15)=15(15)-16=225–16=209