Step-by-step explanation:
this is clearly not a linear sequence (the terms don't have the same difference).
so, it has to be a geometric sequence.
the common ratio is r.
s2 = s1 × r
16 = 64 × r
r = 16/64 = 1/4
control :
s3 = s2×r
4 = 16 × 1/4 = 4
correct.
Well, for -6d to equal -13d, d would have to be 0 to satisfy this equation
Range is the difference between the largest and the smallest variable. If the range is 18 and the smallest number is 9. Add 9 to 18.
9+18= 27. 27 is the largest number.