Ada yang bisa jawab pake cara lengkapnya?

7)
Cari dulu persamaan garisnya utk mencari titik potongnya.

Pada garis yg melewati (0 , 12) dan (6 , 0)

(y - y1) / (y2 - y1) = (x - x1) / (x2 - x1)
(y - 12) /(0-12) = (x-0)/(6-0)
6(y - 12) = -12x
--------------------- ÷ 6
y -12 = -2x
2x + y = 12 .... (1)


Pada yg lewat (0,8) dan (12,0)
y - y1 / y2 - y1 = x-x1/x2-x1
y-8/0-8 = x-0/12-0
12(y - 8) = -8x
-------------------- ÷ 4
3(y - 8) = -2x
3y - 24 = -2x
2x + 3y = 24 .... (2)

2x + 3y = 24
2x + y = 12
---------------- -
2y = 12
y = 6

2x + (6) = 12
2x = 6
x = 3

Titik potong = (3,6)

skrg liat hpnya..

hp ny menyinggung (0,12) (3,6) dan (12,0)

z = 2x + 3y
masukkan saja
f(0,12) = 2(0) + 3(12) = 36
f(3,6) = 2(3) + 3(6) = 24
f(12,0) = 2(12) + 3(0) = 24

maks : 36 (E)
8)
(f + g)(x)
= f(x) + g(x)
= x - 3 + 2x³ + 5x
= 2x³ + 6x - 3 (A)

9)
(fog)(x) = 3x² - 1
f(g(x)) = 3x² - 1
2g(x) - 5= 3x² -1
2g(x) = 3x² + 4
g(x) = (3/2)x² + 2

10)
(fog)(x) = f(g(x))
f(2x) = 2x + 4

y = 2x + 4
y -4 = 2x
x = (y - 4) / 2
(fog)^-1(x) = (x - 4) / 2
atau ½x - 2 (E)

11)

f(x) = 3x + 4/2x -1
y = 3x + 4 / 2x - 1
2xy - y = 3x + 4
2xy - 3x = y + 4
x(2y - 3) = y + 4
x = (y + 4) / (2y - 3)
f^-1(x) = (x + 4) / (2x - 3)

B