tolong yang tau skornya besar

jawaban diberikan dalam bentuk gambar

semoga jelas dan membantu

1. f(x) = 2x - 3
    (g o f)(x) = 4x² -16x + 18
    g(f(x)) = 4x² -16x + 18
    g(2x - 3) = 4x² -16x + 18                  misalkan 2x - 3 = a maka x = (a + 3)/2
    g(a) = 4((a + 3)/2)² - 16((a + 3)/2) + 18
            = (a + 3)² - 8(a + 3) + 18
            = a² + 6a + 9 - 8a - 24 + 18
            = a² - 2a + 3
  jadi g(x) = x² - 2x + 3

2. f(x) = 8x + 5
    g(x) = x + 2
    (f o g)(x) = f(g(x))
    15 = f(x + 2)
    15 = 8(x + 2) + 5
    15 = 8x + 16 + 5
    8x = 15 - 21
    8x = -6
     x = -3/4

3. f(x) = x² - 2
    g(x) = 2x + 1
    (f o g)(x) = f(g(x))
                   = f(2x + 1)
                   = (2x + 1)² - 2
                   = 4x² + 4x + 1 - 2
                   = 4x² + 4x -1

4. f(x) = x/(x - 1)
    y = x/(x - 1)
    y(x - 1) = x
    xy - y = x
    xy - x = y
    x(y - 1) = y
    x = y/(y - 1)
    f⁻¹(x) = x/(x - 1)

5. f(x) = x + 3 dan untuk x = 2 --> f(x) = 5
    f(x)² + 5f(x)² - 3f(x) = 5² + 5×5² - 3×5
                                  = 135