Can someone help i don’t understand this

Part a : solve -vp + 40 < 65 for v part b : solve 7w - 3r = 15 for r show your work .

11. a particular type of cell doubles in number every hour. which function can be used to find the number of cells present at the end of h hours if there are initially 4 of these cells? a. n = 4 ()" b. n = 4(2)" c. n = 4 + (2)" din = 4 +"

Ihave trouble finding the nth term of a linear sequence