Treat this as you would the quadratic equation x^2 - 4x - 3 + 0. Solve this by completing the square:
x^2 - 4x + 4 - 4 - 7 = 0
(x^2 - 4x + 4) = 11
(x-2)^2 = 11, and so x-2 = plus or minus sqrt(11).
Graph this, using a dashed curve (not a solid curve). Then shade the coordinate plane ABOVE the graph.
Answer:
5
Step-by-step explanation:
The probability of tails is 1/2, so the expected value is (1/2) (10) = 5.
DE + EF = DF
x - 2 + 6x + 4 = 8x - 2
7x + 2 = 8x - 2
2 + 2 = 8x - 7x
4 = x <===
