An equation is:
2(x+3)-7=9
Distribute the 2
2(x)+2(3) -7=9
2x+6-7=9
Combine like terms
2x-1=9
Add one to both sides
2x-1+1=9+1
2x=10
Divide both sides by two to isolate the variable.
2x/2=10/2
x=m
The rock's height is increasing in the interval from 0 seconds to 3 seconds.
At time 0 the rock starts moving upward from 52 foot until it reachs 180 foot height (time 3 seconds). Then the rock starts to descend, which means that the height starts to decrease.
<span>Well, they couldnt have studied negative time.. So Id say the domain is \(x \ge 0\) where \(x\) is the time they studied.</span>