Step-by-step explanation:
do you mean less than or equal to
x/3<= -6 x 3
x<= -18
Answer:
Marco's age is 7 years old
Step-by-step explanation:
Let
x ----> Marco's age
y ----> Paolo's age
we know that
----> ----> equation A
----> equation B
substitute equation A in equation B
Solve the quadratic equation
The formula to solve a quadratic equation of the form
is equal to
in this problem we have
so
substitute in the formula
Remember that the solution cannot be a negative number
so
The solution is x=7
therefore
Marco's age is 7 years old
Answer:
b. $28
Step-by-step explanation:
We have these following probabilities:
0.4 = 40% probability of $40
0.2 = 20% probability of $30
0.2 = 20% probability of $20
0.2 = 20% probability of $10
The expected value is:
We multiply each value by its probability. So
So the correct answer is:
b. $28