Circle P has a radius of 5cm. Point Q lies on circle P, and the equation of PQ is y=2/5x+3. Which equation could be the equation of a line tangent to circle P at point Q? I know that 5x + 2y = 7 is the correct answer, but I would like to know why it is correct, can someone please explain?

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?

Given the following linear function sketch the graph of the function and find the domain and range. ƒ(x) = -5x + 4

Which number is located at point a on the number line? a number line is shown from negative 10 to 10 with each interval mark on the number line representing one unit. point a is labeled one interval mark to the right of negative 5.