The slope of the line that contains the points (1, -1) and (2, 3) is 4. What is the y-intercept? A. 5
B. 4
C. -4
D. -5

Please help me out & thank you

Part a: explain why the x-coordinates of the points where the graphs of the equations y = 2−x and y = 8x+4 intersect are the solutions of the equation 2−x = 8x+4. (4 points) part b: make tables to find the solution to 2−x = 8x+4. take the integer values of x between −3 and 3. (4 points) part c: how can you solve the equation 2−x = 8x+4 graphically? (2 points)