tolong bantuin no 14&15 sama caranya ya biar aku paham, makasih

14) dijabarin
(4x⁴+4x²+1)x³ dx
(4x^7 + 4x^5 + x³) dx
(4/(7+1))x^8 + (4/(5+1))x^6 + 1/4x^4 + C
½x^8 + ⅔x^6 + ¼x^4 + C

15) misal x² + 3 = u
2x dx = du
dx = du/2x
2x(x² + 3)^½ dx
2x u^½ du/2x
(2x/2x) u^½ du
(1 / (1+½)) u^(½+1) + C
(1/(3/2)) u^3/2 + C
(2/3) u√u + C
(2/3) (x²+3)√(x²+3) + C