Question

Dik = f(x) = 2 (x + 3) dan g(x) = 5(3-x)

Tentukan :
a. f(x) + g(x)
b. f(x) - g(x)
c. f(x) . g(x)
d. (f + g) (2)
e. (f - g) (3)
f. (f . g) (-3)
yang bisa tolong bantuannya yaa...

Answer 1

Dik = f(x) = 2 (x + 3) dan g(x) = 5(3-x) Tentukan :
a. f(x) + g(x)
=> 2 (x+3) + 5 (3-x) = 2x + 6 + 15 - 5x = -3x + 21

b. f(x) - g(x)
=> 2 (x+3) - 5 (3-x) = 2x + 6 - 15 + 5x = 7x - 9

c. f(x) . g(x)
=> { 2 (x+3)} . {5 (3-x) } = (2x + 6) . (15-3x) = 12x - 6 + 90

d. (f + g) (2)
=> 2 (x+3) + 5 (3-x) = 2x + 6 + 15 - 5x = -3x + 21 = -3 (2) + 21 =- 6 + 21 = 15

 e. (f - g) (3)
=> 2 (x+3) - 5 (3-x) = 2x + 6 - 15 + 5x = 7x - 9 = 7 (3) - 9 = 21 - 9 = 12

f. (f . g) (-3)
=> { 2 (x+3)} . {5 (3-x) } = (2x + 6) . (15-3x) = 12x - 6 + 90
= 12 (-3) - 6 + 90
= -36 - 6. 9 + 90
= - 42 + 90
= 48