Assuming that each marble can be picked with equal probability, we notice that there is a total of
marbles, of which 2 are red.
So, the probability of picking a red marble is
In fact, as in any other case of (finite) equidistribution, we used the formula
Answer:
Option A.
Step-by-step explanation:
The given equation is
Step 1: Multiply both sides by (x-4).
Step 2: Multiply both sides by 7.
Step 3: Using distributive property.
Step 4: Isolate all terms on one side.
Step 5: Find factors by splitting the middle term.
Step 6: Using zero product property, we get
It means student solved the equation correctly.
Therefore, the correct option is A.