Describe how you would Compare √2 and √11

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

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.