If you expand this equation first
You get -4u+6+3u=3u+24
And if you simplify that you get:
-u+6=3u+24
Now you need to solve this equation to find u
First bring 3u to the other side to -u-3u (the positive changes to negative)
Now the equation is
-4u+6= 24
Take 6 of both sides
-4u=24-6= 18
-4u= 18
So u= -18/4
Which simplifies to -9/2
Answer: -9/2
SOLUTION
From the sequence give
–3, 1, 5, 9, . . .
The first term, a = -3
The common difference, d = 4 (gotten by adding 4 to the next term).
The number of terms required n = 6.
Formula for sum of an arithmetic sequence is given by

Substituting these values into the equation above we have

Hence, the answer is 42, option B
Well the answer would be 120=120 and 68=68