Steps to solve:
9(d - 93) = -36d
~Distribute
9d - 837 = -36d
~Subtract 9d to both sides
-837 = -45d
~Divide -45 to both sides
18.6 = d
Best of Luck!
Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.
If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:
E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]
Or, if you're given the expectation and variance of <em>X</em>, you have
Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²
→ E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]
Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.
Answer:
12 different sums
Step-by-step explanation:
there's three darts and three numbers.
if you use the factorial 3! for both the number of darts and the score numbers and add the two together, you would get twelve :
( 3! = 3*2*1 = 6 ) * 2
6 + 6 = 12
or you could just write out all the combinations like this :
2+2+2
2+2+5
2+5+5
2+5+8
2+8+8
5+5+2
5+5+5
5+5+8
5+8+8
8+8+2
8+8+5
8+8+8
