Trying as hard as I can, but I'm not sure if these multiple choice q's are correct.

Question

2.   What are the solutions of the equation

x2 + 4x = 96?  

2, –48
–12, 8
–2, 48
12, –8

My answer: _12, 8

3.   What are the solutions of the equation

x2 + 14x = –130? 

2, –16
10, –13
–2, 16
no solution

My answer: no solution.

4.   A rocket is launched from atop a 105-

foot cliff with an initial velocity of 156 ft/s.

The height of the rocket above the ground

at time t is given by h = –16t2 + 156t +

105. When will the rocket hit the ground

after it is launched? Round to the nearest

tenth of a second. 

4.9 s

9.8 s

0.6 s

10.4 s

Myanswer: 9.8 s

Answer 1

2. x²+4x-96=(x+12)(x-8)=0 so x=-12 or 8 is the solution.

3. x²+14x+130=0 has no solutions.

4. When h=0, -16t²+156t+105=0, or 16t²-156t-105=0. 

t²-(156/16)t-105/16=0,

t²-(39/4)t+(39/8)²-(39/8)²-105/16=0,

(t-39/8)²-1941/64=0,

(t-39/8-√1941/8)(t-39/8+√1941/8)=0.

The only positive solution is (39+√1941)/8=10.4 seconds (approx).