Does anyone know how to some 4,5,6?

Use the Law of Cosines

NOTE: Please check my numbers.  The numbers were blurry in the picture.

 4) b = 29.8

                5) a = 24.3

                6) C = 53.1°

Step-by-step explanation:

4)

b² = a² + c² - 2ac · cos B

   = (20)² + (25)² - 2(20)(25) · cos 82°

   = 400 + 625 - 1000 (0.139)

   = 888

√b² = √888

 b   ≈  29.8

5)

a² = b² + c² - 2bc · cos A

   = (18)² + (28)² - 2(18)(28) · cos 59°

   = 324 + 784 - 1008 (0.515)

   = 590.49

√a² = √590.49

 a   ≈  24.3

6)

c² = a² + b² - 2ab · cos C

15² = (15)² + (18)² - 2(15)(18) · cos C

225 = 225 + 324 - 540 cos C

 53.1   ≈  C

20

step-by-step explanation:

d is the correct answer

step-by-step explanation:

x= 8 because 3x = 3 * 8, and 3*8 = 24