Find the sum 12/15-1/6

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¯¯¯¯¯¯¯¯)?

Use the distributive law to multiply. 3(4x + 5y + 6)

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8