Answer:
The first listed equation is the correct equation to solve
The correct answer is: t = 5 seconds
Step-by-step explanation:
Let me mention first that there is an error in the statement that the gravitational pull of the Earth is 16 ft/s^2. It is in fact 32 ft/s^2, and the actual equation uses half of the acceleration multiplied by the square of the variable time, so it gives as final expression :

and we want to find the value/s for "t" that make this equation equal zero (when it reaches the ground and the object just touches the ground. This makes the equation we want to solve:

which solving for "t" becomes:

So we adopt the positive answer (positive time) since the negative value has no physical meaning for this problem.
That is: t = 5 seconds
 
        
             
        
        
        
-15m -30 = -12m +6
3m = 36
m= 36/3 =12
        
                    
             
        
        
        
Answer:
في الأسبوع الماضي ، اشترى تشين جالونًا من البنزين للغالون الواحد. هذا الأسبوع اشترى جالونًا من البنزين مقابل الدولار للغالون
Step-by-step explanation:
 
        
             
        
        
        
I dont think the answer is 129 unless you typed the problem in wrong. Order of operations say to do everything inside the perenthesis first so you would do the 3*2 which is 6 then divide the 12 by 6 and you get 2. so your new equation is 8^2+9(2)-7. Next distribute the 9 to the 2 that is inside the perenthesis. Square root the 8 also. Now it is 49+18-7. The answer would be 60 ...?