Find the equation Of the line passing through the points (7, 2) and (9, 1)

Having a hard time understanding this question (see attachment).

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

What is the value of -3/4 to the 4th power? -256/81 -81/256 81/256 256/81