Why is sqrt of x^2 = x, while sqrt of y^2 = +-y (positive or negative y)?

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?

The police chief wants to know if the city’s african americans feel that the police are doing a good job. identify the management problem (i. e dependent variable) and identify the independent variable.