Help me i need the info to his

Find the domain of the following expression: 1/(√x)-2

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?

Aline has a slope of negative 1/4 the past two points -5/4 and 1 what is the equation of the line