17*17 i forget how multiplication works (oops oof)

Aproduction manager test 10 toothbrushes and finds that their mean lifetime is 450 hours. she then design sales package of this type of toothbrush. it states that the customers can expect the toothbrush to last approximately 460 hours. this is an example of what phase of inferential statistics

Parabolas y=−2x^2 and y=2x^2 +k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.

Tim open up a new saving account with a $50 deposit and plant to deposit $20 per week into the same account.write an expression to represent the total amount in his savings account.