Answer:
x = 10
Step-by-step explanation:
1) Subtract x from both sides.
4x − x = 30
2) Simplify 4−x to 3x
3x = 30
3) Divide both sides by 3
x = 
4) Simplify
to 10
x = 10
The first one: whole equation when move1 to the left, same with the second I believe
We can figure this out using the explicit formula.

n represents the term we are looking for.
f(1) represents the first term in the sequence, which in this case, is 7.
d represents the common difference, which in this case, is +3.
f(n) = 7 + 3(n - 1)
f(n) = 7 + 3n - 3
f(n) = 4 + 3n
Now, we can input 214 for n and solve.
f(214) = 4 + 3(214)
f(214) = 4 + 642
f(214) = 646
The 214th term in this sequence is 646.