Trinomial problem

[gcooper]

A ball is thrown upward with an initial speed of 160 feet per second. When will the ball be at a height of 336 feet?

The formula is h = vt - 16t^2, where v is the initial speed and t is the time in seconds.

I tried this:



Now, I can't find 2 numbers to multiply to 21 and add to -16. Where and what did I do wrong?

 

[wjm11]

A ball is thrown upward with an initial speed of 160 feet per second. When will the ball be at a height of 336 feet?

The formula is h = vt - 16t^2, where v is the initial speed and t is the time in seconds.

I tried this:

View attachment 4552

Now, I can't find 2 numbers to multiply to 21 and add to -16. Where and what did I do wrong?

160/16 does not equal 16. I'm sure you can handle this with that correction. Your approach is fine.

 

[gcooper]

I can't believe I missed that...god I went over it so many times yet I never noticed it....

 

[lookagain]

View attachment 4554I can't believe I missed that...god I went over it so many times yet I never noticed it....

gcooper, it is correctable, because you haven't exceeded the "statue/statute of limitations."

 

[HallsofIvy]

Go stand in the corner for 16 minutes :cool:

Or 10 minutes- whichever comes first.