how do you do longhand

Use the t-distribution table to find the critical value(s) for the indicated alternative hypotheses, level of significance a, and sample sizes n, and n,- Assume that the samples are independent, normal, and random. Answer parts (a) and (b). He : H, > H2, a = 0.10, n, = 18, n2 =8 (a) Find the critical value(s) assuming that the population variances are equal. (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.)