tolong y ka di jawab dengan cara

12) f(x) = 10 - 2x²
f(-4) = 10 - 2(4)² = 10 - 2(16) = 10 - 32 = - 22 ( C )

13) g(x) = ⅓(x + 4)
g(a) = ⅓(a + 4)
- 2 = ⅓ ( a + 4)
a + 4 = - 2 ÷ ⅓
a + 4 = - 2 × 3/1
a + 4 = - 6
a = - 6 - 4
a = - 10 ( A)

14) f(x) = x² - 5x
f(4) = (4)² - 5(4) = 16 - 20 = - 4
f(-2) = (-2)² - 5(-2) = 4 + 10 = 14
f(4) - f(-2) = - 4 - 14 = - 18 ( D)

15) f(x) = x² - 4x
f(a + 3) = (a + 3)² - 4(a + 3)
= a² + 3a + 9 - 4a - 12
= a² - a - 3 ( A )