EXPLANATION
If the first two terms of an arithmetic sequence are 7 and 4, then we know that an arithmetic sequence has a constant difference d and is defined by

Check wheter the difference is constant:
Compute the differences of all the adjacent terms:

Replacing terms:
4-7 = -3
The difference between all of the adjacent terms is the same and equal to
d = -3
The first element of the sequence is


Therefore, the nth term is computed by
d= -3

Refine
d= -3 ,

Now, replacing n=7

So, the answer is -11.
You have to subtract the 6 first and then divide the rest by 1/8.
34-6=28
28×1/8=224
For this, we will be using the quadratic formula, which is
, with a=x^2 coefficient, b=x coefficient, and c = constant. Our equation will look like this: 
Firstly, solve the multiplications and the exponents: 
Next, do the addition: 
Next, your equation will be split into two:
. Solve them separately, and your answer will be