David gave 1/5 of his oranges to his brother. his brother got 15 oranges. he gave his friend donny 1/3 of the remainder.
a) how much oranges did david have originally? b) how many did donny get? c) how many oranges was david left with?

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

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.

State one method by which you can recognize a perfect square trinomial.