tolong dijawab no 7-9 ya gann

7 . h(x) = 4x + 12
a . h(n) = n
     4n + 12 = n
      3n = -12
        n = -4
b. h(2n) = 4n
    4(2n) + 12 = 4n
     8n + 12 = 4n
     4n = -12
       n = -3


8. 
f(x) = 5x - 8
g(x) = 3x + 4

f(n) = g(n)
5n - 8 = 3n + 4
2n = 12
n = 6
maka
f(6) =  5(6) - 8 = 30 - 8 = 22
g(6) = 22

f(3n) = f(18)
        = 5(18) - 8
        = 82
g(4n) = g(24)
         = 3(24) + 4
         = 76
jadi f(3n) + g(4n) = 82 + 76 = 158


9 . 
g(x) = x² + 7x - 3
h(x) = x² + 11x + 9

g(m) = h(m)
m² + 7m - 3 = m² + 11m + 9
4m = -12
m = -3

g(4m) - h(4m)
= g(-12) - h(-12)
= (-12)² + 7(-12) - 3 - ((-12)² + 11(-12) + 9)
= 144 - 84 - 3 - 144 + 132 - 9
= 36