$30\left(\frac{1}{-35}\right)=\square$ (Type an integer or a simplified fraction.)

Step 1 ：Understand the problem: We are asked to multiply an integer by a fraction.

Step 2 ：Set up the problem: We can write the problem as \(30 \times \left(\frac{1}{-35}\right)\).

Step 3 ：Multiply: When we multiply 30 by \(\frac{1}{-35}\), we get \(-\frac{30}{35}\).

Step 4 ：Simplify: We can simplify \(-\frac{30}{35}\) by dividing both the numerator and the denominator by their greatest common divisor, which is 5. So, \(-\frac{30}{35}\) simplifies to \(-\frac{6}{7}\).

Step 5 ：Check the result: \(-\frac{6}{7}\) is a simplified fraction, and it meets the requirements of the problem.

Step 6 ：\(30\left(\frac{1}{-35}\right)=-\frac{6}{7}\)

Step 7 ：\(\boxed{-\frac{6}{7}}\) is the final answer.