Question

Suatu fungsi dirumuskan f(x)=ax + b. jika f(-2)=14 Dan f(3)= -1, maka nilai f(7) adalah ...

Answer 1

Verified answer

F(x) = ax + b

f(-2) = -2a + b = 14
f(3) =   3a + b = -1
       --------------------- (-)
           5a = -15
            a = -3

3a + b = -1
3(-3) + b = -1
b = -1 + 9
b = 8

jadi rumus fungsi f adalah
f(x) = -3x + 8

f(7) = -3(7) + 8
f(7) = -21 + 8
f(7) = -13

Answer 2

F(x)=ax+b f(-2)=-2a+b=14 f(3)=3a+b=-1 -2a+b=14 3a+b=-1 -5a=15 a=-3 -2a+b=14 -2(-3)+b=14 6+b=14 b=8 f(x)=ax+b f(7)=-3(7)+8 f(7)=-21+8 f(7)=-13