tolong bantuanya ya.. sama caranya juga

Aritmatika
Limit
Turunan

21)
Sn = n/2 (2a + (n -1)b)
S40 = 40/2 ( 2(12) + (40-1)2)
S40 = 20(24 + 78)
S40 = 20(102)
S40 = 2040

D

23)
Nilai = (b-q)/2√a
= (3-5)/2√1
= -2/2
= -1

E

24)
f(x) = (3x - 1)(x² + 3x - 4)²

u = 3x - 1
u' = 3

v = (x² + 3x - 4)²
v' = 2(x² + 3x - 4)(2x + 3)
v' = (4x + 6)(x² + 3x - 4)
v' = 4x³ + 12x² - 16x + 6x² + 18x - 24
v' = 4x³ + 18x² + 2x - 24

f'(x) = u'v + uv'
= 3(x² + 3x - 4) + (3x - 1)(4x³ + 18x² + 2x - 24)

f'(-1)
= 3((-1)²+3(-1)-4))² + (3(-1)-1) . (4(-1)³ + 18(-1)² + 2(-1) - 24)
= 108 + 48
= 156

A