Please help me with this

What is the missing step in this proof ?

What else equals 42 and 30 for multiply

Which of the following are arithmetic sequences? check all that apply. a. 0.3, 0.6, 0.9, 1.2, 1.5, b. 2, 3, 6, 11, 18, c. 150, 147, 144, 142, d. 2, 4, 9, 16, 25,