Solve the systems and show your working

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

What is the period of the sinusoidal function ?

The graph below shows the line of best fit for data collected on the number of cell phones and cell phone cases sold at a local electronics store on twelve different days. number of cell phone cases sold 50 * 0 5 10 15 20 25 30 35 40 45 number of cell phones sold which of the following is the equation for the line of best fit? a. y = 0.8x b. y = 0.2x c. y=0.5x d. y = 0.25x