Solve for X in y=12x-5

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¯¯¯¯¯¯¯¯)?

Lines a and b are perpendicular. if the slope of line a is 3, what is the slope of line b?

Each unit cost 14p, how much would 942 units cost?