In this case you the probabilities can be multiplied similarly to if you flipped a coin twice. .45 * .80 = .36
5x-2x+6x+40-9+1-x+3x-8+15+7
First you would combine like terms:
5x - 2x + 6x - x + 3x = 11x and
40 - 9 + 1 - 8 + 15 + 7 = 46, so the simplified expression would be
11x + 46
I just learned about it. Simple!
6x=5x+7
Subtract 5x from both sides.
-5x -5x
You end up with
1x=7 or x=7