One red marble, two white marbles 1 purple and three blue marbles are in a bag. Two marbles are drawn from the bag without replacement what is the probability that both marbles are blue

What is the product of the radical expression. (7-2square root) (8+2 square root)

Arley is building a model of a city map. in one part of the city, three roads form a right triangle, which harley draws as triangle abc, with the following measures: m∠b=90° and m∠a=30°. in his scale model, the hypotenuse of triangle abc, ac¯¯¯¯¯¯¯¯, has a length of 817−−√ cm. what is the value of a (the length of bc¯¯¯¯¯¯¯¯)?

Ineed here’s a picture of the question