Please help me what is a NOW a/4 − 5/6 = −1/2

1. the following set of data represents the number of waiting times in minutes from a random sample of 30 customers waiting for service at a department store. 4 5 7 10 11 11 12 12 13 15 15 17 17 17 17 17 18 20 20 21 22 22 23 24 25 27 27 31 31 32 a. determine the number of classes and class interval.

Use the x-intercept method to find all real solutions of the equation.x^3-10x^2+27x-18=0

What is sin 7x/4 ? i need on this urgent trig