Answer:
30
Step-by-step explanation:
So she starts out with -1 dollars. Then she borrows 4 more and gets to -5 dollars. If she pays him back 3 dollars, she is left still owing him 2 dollars as her balance is at -2 dollars.
-1 - 4 + 3 = x
X = -2
Answer:
.
Step-by-step explanation:
Probability that the car encounters a green light on the first day:
.
To meet the question's conditions, the car needs to encounter another green light on the second day. Given that the colors of the light on each day are "independent," the chance that there's a green light followed by another green light will be
.
- Condition is met on the first two days and green light on the third day:
. - Condition is met on the first three days and green light on the fourth day:
.
To meet the condition on the fifth day, there needs to be a yellow light. The probability that the condition is met on the first four days and on the fifth day will be
.
To meet the condition on the sixth day, all prior days should meet the conditions. Besides, there needs to be a red light on the sixth day. 
- Seventh day:

- Eighth day:
- Ninth day:
- Tenth day:
The question asks that the condition be met on all ten days. As a result, the probability of meeting the condition will be equal to the probability on the tenth day:
.
Tnemos el sisema de ecuaciones:

Podemos resolverlo por eliminación sumando ambas ecuaciones y eliminando y. Asi podemos resolver para x:

Ahora podemos resolver para y con cualquiera de las dos ecuaciones:

Respuesta: x=-3, y=0