diketahui fungsi f(x)=ax+b.jika f(-1)=-7 dan f(4)=18,tentukan: a)nilai a dan b b)rumus fungsi f(x) c)nilai f(-3)dan f(7) d)nilai k sehingga f(k)=8

f(x) = ax + b

f(-1) = -1a + b = -7
f(4) = 4a + b = 18
______________ -
= -5a = -25
= a = -25/-5
= a = 5
-1a + b = -7
-1.5 + b = -7
-5 + b = -7
b = -2

a) a = 5 , b = -2
b) Rumus fungsi f(x) = 5x + (-2)
c) f(-3) = 5.-3 + (-2) = -17
f(7) = 5.7 + (-2) = 33
d) nilai k
f(k) = 5k + (-2) = 8
= 5k = 10
= k = 10/5
= k = 2