materi integral mohon bantuannya, soal akhir saja

InteGRal  SubstiTusI

(3)
∫ 10x (20x² -1)⁴ dx
= (10 x / (40 x) (1/5) (20x² -1)⁵ + c
= ¹/₄ (¹/₅)  (20 x² -1)⁵ + c
= ¹/₂₀ (20 x² -1) + c

(4)
∫ (4x - 2) / √(x²  - x  + 5)  dx =
∫ (4x - 2) (x² - x + 5)^(-1/2)  dx
u = x² - x
du =  ( 2x -1) dx
(4x - 2) dx  = 2(2x - 1)  dx = 2 du

∫ (2 du) (u)^(-1/2)  = 2(2)(u)^(1/2) + c
=  4 u^(1/2) + c
= 4√(x² - x + 5) + c