The easiest way is to use (& to memorize) the sum formula for a AP:
Sum = 1st term added to the last term & multiplied by half the number of terms
S = (a+l)n/2
S = (5 + 53)(7/2) = 203
Well try working on the problem first
Mainly all you do is subtract , and it'll give you the right estimate
What are you specifially looking for? simplified it would be 10 and as a fraction 10 over 1
your answer
hope it will work for you
