Question

Fungsi
1.Ditentukan f(x)=x²-5n.Jika nilai f(5)=10,maka nilai n=......?
2.Fungsi h dinyatakan dengan rumus h(x)=px+q.Jika h(4)=-28 dan h(-5)=26,maka h(-12)=......?
Tambahin caranya yh ak butuh banget

Answer 1

1. f(x)=x² - 5n
    f(5)= 5² - 5n = 10
       25 - 5n = 10
       25 - 10 = 5n
         15 = 5n
           3 = n

Answer 2

1) f(x) = x² - 5n
f(5) = 10
5² - 5.n = 10
25 - 5.n = 10
25 - 10 = 5.n
15 = 5.n
n = 15:5
n = 3




2) h(x) = px + q
h(4) = 4p + q = -28
h(-5) = -5p + q = 26
____________ -
9p = -54
p = -54/9
p = -6

p = -6 → 4p + q = -28
4.(-6) + q = -28
-24 + q = -28
q = -28 + 24
q = -4

maka didapat rumus fungsi :
h(x) = px + q
h(x) = -6x + (-4)
h(x) = -6x - 4
jadi,
h(-12) = (-6).(-12) - 4 = 72 - 4 = 68