A large concrete mixing machine can mix a certain amount of concrete in 12 hours, while a smaller one can mix the same amount in 20 hours, Mixing simultaneously, how long would it take both machines to mix the same
amount of concrete?

Need ! give step by step solutions on how to solve number one \frac{9-2\sqrt{3} }{12+\sqrt{3} } number two x+4=\sqrt{13x-20} number three (domain and range) f(x)=2\sqrt[3]{x} +1

The conversion factor relating feet to meters is 1 ft=0.305 m. keep in mind that when using conversion factors, you want to make sure that like units cancel leaving you with the units you need. you have been told that a certain house is 164 m2 in area. how much is this in square feet?

`if you have a set of parallel lines a and b cut by transversal x, if angle 1 = 167 degrees, what is angle 4 and why. also what is the measure of angle 5 and why? you need to use the names of the angle relationship and explain. ''.