I need help

[tami.smith]

I am starting a math course and have no idea how to do the work can someone please explain:

2y+21y²-3

 

[Deleted member 4993]

I am starting a math course and have no idea how to do the work can someone please explain:

2y+21y²-3

What do you need to do with the expression above?

 

[HallsofIvy]

As far as "explaining" is concerned, that means "whatever number multiply it by 2, multiply it by itself and multiply that by 3, add those, then subtract 3.

As far as a "problem", I see no "problem". What were you to do with that polynomial?

 

[DrPhil]

I am starting a math course and have no idea how to do the work can someone please explain:

2y+21y²-3

You are given a quadratic expression - that is, the highest power of the variable y is y². You haven't actually asked a question, but it is most likely that you are supposed to factor the expression into two binomials. There are several ways to do this, but mostly we start by looking at the coefficients and seeing if we can find rational solutions. Lets write it with the y² first:

21 y² + 2 y - 3

What integers can multiply together to give 21? Either 21*1 or 7*3, so the first terms of the binomials will be
either (21y ...)(y ...). ..or. ..(7y ...)(3y ...).

What integers multiply to give -3? Either 3*(-1) or (-3)*1, so the second terms of the binomials will be
either (... + 3)(... - 1). ..or. ..(... - 3)(... + 1)

Your task is to find a combination of factors such that the cross-terms add up to the middle term, +2y.

IF YOU CAN'T FIND A SOLUTION this way, you can always set the expression equal to zero and use the quadratic formula to find its roots.

 

[lookagain]

I am starting a math course and have no idea how to do the work can someone please explain:

2y+21y²-3

tami.smith, please type out the exact complete problem.