It seems like you have uploaded an image with several integral questions that require substitution to solve. Here's a breakdown of the questions:

a) $\int \frac{x}{3 - x^2} \, dx$

b) $\int \frac{\cot(x)}{\sin(x)} \, dx$

c) $\int_0^{10} e^{10x+3} \, dx$

d) $\int_{\frac{1}{\pi}}^{\frac{2}{\pi}} \frac{\sin\left(\frac{1}{x}\right)}{x^2} \, dx$

Would you like to go through the solutions for these problems step by step? If so, I can help with each one individually. Let me know if you'd like a detailed explanation or if you have any specific questions about the integrals!