Diketahui fungsi f = 5x - 8, Tentukan: a. f = -4 dan f = 3, b. jika f(a) = 12, berapa nilai a ?
Diketahui fungsi f = 5x - 8, Tentukan: a. f = -4 dan f = 3, b. jika f(a) = 12, berapa nilai a ?
Pembahasan:
f = 5x - 8
a. f(-4) = 5(-4) - 8 = -20 - 8 = -28
f(3) = 5(3) - 8 = 15 - 8 = 7
b. fx =5x - 8
f(a) = 5a - 8
12 = 5a - 8
12 + 8 = 5a
20 = 5a
a = 20/5
a = 4