Step-by-step explanation:
6a
Sn = n/2 [2a + (n-1) d]
(2Sn)/ n = 2a + (n - 1) d
2a + (n-1) d = (2Sn)/n
(n-1) d = (2Sn - 2a)/n


6b

d = ¹/16
7a.
E = (mv²)/2 + mgh
E = m( v²/2 + gh)
E/m = v²/2 + gh
E/m - gh = v²/2
2(E/m - gh) = v²
so

7b.

v = 14 m/s
Answer:
h = 22 for Rachel
Step-by-step explanation:
20 + h = 42
h = 42 - 20
h = 22
Answer:
Ya the person above me is right 4cd
After h hours A has 6000 - 2000h cells and B has 2000 - 1000h. Equating them as one form:
6000 - 2000h = 2000 - 1000h
-2000h + 1000h = 2000 - 6000
-1000h = -4000
h = -4000/-1000 = 4 hours