Step-by-step explanation:
18 seconds to hour
18÷3600= 0.005 hour
accelerstion= velocity÷ time
60 mph÷ 0.005 = 12,000m/h^2
The answer to your problem is 17
Since you have y alone on one side of the equation......
Use substitution and plug in 1/2x-4 for y in the other equation.

Distribute

Combine like terms

Add 8 to both sides

Divide by 4
and 
Plug this value in for x

Simplify

Multiply everything by 8 and simplify

Divide.....

Your answers are:

Answer:
0.01
Step-by-step explanation:
If you convert 10 into a decimal it's just 0.1, multiply 0.1 by itself only one time because the exponent is 2 and you get 0.01