PreCalc
posted by Elllie on .
Please check answer and help with one of them:
1. check please
car in an accident speed of car is the s, d is length of skid=30 feet
f is coefficient=0.5
use formula to find
s=sqaure root of 30*f*d
My answer is 21.21 because I took square root of 30(0.5)(30)
2. this one is baffling to mehow do I do this one3 times square root of (x+1) is less than or equal to 7 Please helpThank you

I posted earlier but no one answered so I was hoping if I reposted someone could help

3√(x+1) ≤ 7
9(x+1) ≤ 49
9x+9 ≤49
9x ≤ 40
x ≤ 40/9
of course in √(x+1) , x >1 or else the √ is undefined.
so 1 ≤ x ≤ 40/9 
Thank you for showing me the second onejust one questionis #1 correct the way I did it?
Thank you 
correct if you formula was
s = √(30fd) 
The 30fd was under the square root signthank you