Solve the problem.
mark can remember only the first 4 digits of his friend's phone number. he also knows that the number has 7 digits and that the last digit is not a 0. if mark were to dial all of the possible numbers and if it takes him 21 seconds to try each one, how long would it take to try every possibility?

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar. consider the given table.

Is there a direction u in which the rate of change of f(x, y)equals=x squared minus 3 xy plus 4 y squaredx2−3xy+4y2 at p(1,2) equals 14? give reasons for your answer. choose the correct answer below. a. no. the given rate of change is smaller than the minimum rate of change. b. no. the given rate of change is larger than the maximum rate of change. c. yes. the given rate of change is larger than the minimum rate of change and smaller than the maximum rate of change.

The price of a lawn mower is x dollars. the store is having a 75% end of summer clearance sale. which expression can be used to find the clearance price of the mower? a) .25x b) .75x c) x - .25(75) d) x + .25(75)