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
Answer:
a
Step-by-step explanation:
because it goes to one side to another
Answer:
9???
Step-by-step explanation:
6 trophies on the shelves and 3 that are not.
6 + 3 = 9