Given the sequence 2, x, y, 9. if the first three terms form an arithmetic sequence and the last three terms form a geometric sequence. find x and y.

Can someone pls ! pls answer all. no explanation needed..

When a rectangle is dilated, how do the perimeter and area of the rectangle change?

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.