Question 768196
1) {{{sqrt(3n+12)=sqrt(n+8)}}}
Since both sides are enclosed in a square root, just square both sides & you have:
3n + 12 = n + 8
3n - n = 8 - 12
2n = - 4
n = -2
Substitute -2 for n in the original equation to confirm our answer
 {{{sqrt(3(-2)+12)=sqrt(-2+8)}}}
 {{{sqrt(-6+12)=sqrt(6)}}}
  {{{sqrt(6)=sqrt(6)}}}; which is obviously true

 and
2) An ambulance left the hospital and drove south.
 3 hours later a police car left driving 42 k/h faster attempting to catch up to the ambulance.
 The officer caught up after 2 hours.
 Find the average speed of the ambulance.
Let s = the speed of the ambulance
then
(s+42) = speed of the police car
:
When the police catch the ambulance, they will have traveled the same dist.
Write a distance equation ; dist = speed * time
5s = 2(s+42)
5s = 2s + 84
5s - 2s = 84
3s = 84
s = 84/3
s = 28 k/h is the speed of the ambulance
:
:
Confirm this find the actual dist each traveled, should be the same
5(28) = 140 km
2(28+ 42) = 140 km