Correct. They only want to know how many are 5 cm tall. So we only need to count the 'x' 's in the 5 area, which are 6. You are correct
Answer=6
The general term is obtained by starting with the initial value 5 and then subtracting 4 each time you wish to generate a new term:
a2 = second term = 5+(2-1)(-4) = 5+(-4) = 1
General term:
an = nth term = 5+(n-1)(-4)
Thus, the 21st term is 5+(21-1)(-4) = 5 + (20)(-4) = -75 (answer)
Answer: its 29/35 value....
