I just did the first one but I don't know is it correct
Answer:
It will take 5 stages to reach the surface.
Step-by-step explanation:
-225/50=4.5 or what times 4.5 equals -225
Then the problem says to round up so 4.5 becomes 5.
Answer:
x<-8 or x>1/5
Step-by-step explanation:

First we replace > symbol by = sign

To solve for x we multiply 5x-1 on both sides
x+8 =0
x=-8
5x-1=0 solve for x
x= 1/5
WE got two values x=-8 and x= 1/5
Now we make a number line and check with each interval
x<-8, -8<x<1/5, x>1/5
Pick x= -9 and check with the given inequality

1/46 >0 is true, so x<-8 satisfies our inequality
Pick x= 0 and check with the given inequality

-8 >0 is false , -8<x<1/5 does not satifies our inequality
Pick x= 2 and check with the given inequality

10/9>0 is true , x>1/5 satisfies our inequality
just do what it said and you'll get the answer