If you just want to know what is the least common multiple of 20 and 15, it is 60. Usually, this is written as
lcm(20,15) = 60
The expectation value is simply obtained by multiplying the probability of each outcome by each possible value. These are then summed for each outcome to obtain the expectation value. In the board game, if there is a 60% chance that you will move 4 spaces forward (+4) and a 40% chance that you will move back 2 spaces then expected value for number of spaces is (0.6 x 4) + (0.4 x -2) = 2.4 - 0.8 = 1.6 spaces.
Not possible, you know you have to have at least 5 nickels so substract those first, now your at 4.50. you cant get to 54 coins after that
Slope = "rise over run" the difference in y values divided by the difference in x values
= 6/-3 = -2 = m. It's negative because as x increases, y decreases
plug that into the point slope formula, with either point. generally use the most simple point
y-h= m(x-k) where m= -2 and (k,h) = (2,-2)
y+2 = -2(x-2)
simply if you want
Y = -2x +4 -2 = -2x +2
or
2x +y = 2