How to factor a trinomial with a degree of 3

Step-by-step explanation:

It all depends upon what the terms are.  If each term of the 3 all have a variable you can factor out, then you'd do that first.  For example, if your trinomial looks like this:

you would begin by factoring out the common x, reducing the third degree polynomial to a quadratic which can then be factored many ways.

If that is not the case, then you are factoring higher degree polynomials, and the way I always recommend to my students is the Rational Root Theorem and then synthetic division.

let soccer = x and golf = y

part a

1st equation: x + y = 125

2nd equation: x = y +45

part b

replace x in the 1st equation with the 2nd one:

y + 45 + y = 125

simplify:

2y + 45 = 125

subtract 45 from each side:

2y = 80

divide both sides by 2:

y = 80/2

y = 40

she plays golf for 40 minutes.

part c

no because she plays soccer for 45 minutes longer than golf 40 +45 =   85 minutes, not 80 minutes.