Confused on what do do first . can anyone ?

So solve for q

first factor q out of the summation

now, determine what the summation is


its been a while since ive done summations so i dont remember any tricks but that summation is essentially equal to


or factored to be something like this

which i believe there's a formula for

regardless using a calculator, the summation turns out to be 4/3 i think

you should definitely double check this step

so replacing the summation for 4/3, the equation is now
q*(4/3) =8

pretty easy to solve from here
divide 4/3 to both sides to get q

any questions?