Carbon-14 has a half-life of approximately 5400 years
(a) find a function that gives the amount, a, of carbon-14 in an object after t years. (use the variable a to represent the initial amount).
(b) a leaf is found that contains 25% of the carbon-14 it originally had. approximately how old is it? (round your answer to the nearest year.)

Which statements about the system are true? check all that apply. y =1/3 x – 4 3y – x = –7 the system has one solution. the system consists of parallel lines. both lines have the same slope. both lines have the same y–intercept. the equations represent the same line. the lines intersect.

Adeli owner keeps track of the to-go orders each day. the results from last saturday are shown in the given two-way frequency table. saturday's to-go deli orders in person by phone online total pick up 38 25 31 94 delivery 35 28 34 97 total 73 53 65 191 what percent of the to-go orders were delivery orders placed by phone? a. 14.66% b. 38.41% c. 28.87% d. 52.83%

Recall that two angles are complementary if the sum of their measures is? 90°. find the measures of two complementary angles if one angle is twenty dash nine times the other angle.