Answer:
X=28
Step-by-step explanation:
3x-8=2x+20. So x=28
Between the probability of union and intersection, it's not clear what you're supposed to compute. (I would guess it's the probability of union.) But we do know that

For parts (a) and (b), you're given everything you need to determine

.
For part (c), if

and

are mutually exclusive, then

, so

. If the given probability is

, then you can find

. But if this given probability is for the intersection, finding

is impossible.
For part (d), if

and

are independent, then

.
If the roots to such a polynomial are 2 and

, then we can write it as

courtesy of the fundamental theorem of algebra. Now expanding yields

which would be the correct answer, but clearly this option is not listed. Which is silly, because none of the offered solutions are *the* polynomial of lowest degree and leading coefficient 1.
So this makes me think you're expected to increase the multiplicity of one of the given roots, or you're expected to pull another root out of thin air. Judging by the choices, I think it's the latter, and that you're somehow supposed to know to use

as a root. In this case, that would make our polynomial

so that the answer is (probably) the third choice.
Whoever originally wrote this question should reevaluate their word choice...
Answer:
960
Step-by-step explanation:
We start with the variable "x". Let's call "x" Raina's penny bank.
After adding 360 pennies, at the end, she has 5/8x, or 5/8.
So we start with
(1/4)x + 360 = 5/8x
Let's subtract 1/4x from both sides
360 = 5/8x - 1/4x
Remember, we need to use common denominators to subtract, so 1/4 becomes 2/8
360 = 5/8x - 2/8x
Now we simplify to get
360=3/8x
Multiply the reciprocal of 3/8 to both sides which is 8/3
360 * 8/3 = x
Answer is 960 pennies.
Therefore Raina's bank hold 960 pennies.