Expand and simplify

A:

The half-life of a certain material is 0.002 second. approximately how much of a 14-gram sample will be left after 0.004 second? a. 12 grams b. 3.5 grams c. 0.06 gram d. 7 grams

Complete the frequency table: method of travel to school walk/bike bus car row totals under age 15 60 165 age 15 and above 65 195 column totals 152 110 98 360 what percentage of students under age 15 travel to school by car? round to the nearest whole percent.

The equation for two lines in the coordinate plane are 2dx+y=4 and -6x+y=3, where d represents an unknown value. what value(s) of d would make these lines parallel?