You can use the formula for conditional probability as Puzzling did. However in this problem it is easier just to restrict yourself and enumerate the cases that are left.
<span>There are 4 jacks. One of them is a heart. So the probability is 1/4. </span>
<span>If you want to look at what the formula for conditional probability does, it adjusts your probability by restricting the "universe". </span>
<span>P(heart and jack)/P(jack) </span>
<span>= (1/52)/(4/52) = 1/4</span>
Start by writing what is said:
2x + 4 = -6
From there just solve for x:
Subtract 4 from both sides
2x + 4 - 4 = -6 - 4
2x = -10
Divide by 2 to get x by itself
2x/2 = -10/2
x = -5
Answer:
It would roll in this direction.

Step-by-step explanation:
It would roll to the direction of maximum decrease, which is the -1 times the direction of maximum increase, which is given by the gradient of the function.
Since

For this case, the gradient of your function would be

And -1 times the gradient of your function would be

Then, at

So it would go towards

The magnitud of that vector is

and to conclude it would roll in this direction.
