4times 1 1/5 as a product of a mixed number

What signals you that factoring by grouping is the best method to use when factoring a problem?

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 5x^2 + 10x