Tolong bantuan nya ya kak

Tolong bantuan nya ya kak

Penjelasan dengan langkah-langkah:

$begin{align}a.&int {x}^{3} (2x + 6) : dx \ = & int2 {x}^{4} + 6 {x}^{3} : dx \ =&2 frac{ {x}^{5} }{5} + 6 frac{ {x}^{4} }{4} + c \ = & frac{2}{5} {x}^{5} + frac{3}{2} {x}^{4} + cend{align}$

$begin{align}b.&int (3x - 1) (x + 5) : dx \ = & int3 {x}^{2} + 14x - 5 : dx \ =&3 frac{ {x}^{3} }{3} + 14 frac{ {x}^{2} }{2} - 5x + c \ = & {x}^{3} + 7 {x}^{2} - 5x + cend{align}$