I took the quiz and this what the answer, I hope this help future people that had the same question.
A trapezoid/trapezium is a quadrilateral (4 sided shape) with exactly one pair of parallel sides.
It is a quadrilateral (a closed plane shape with four linear sides) that has at least one pair of parallel lines for sides
The integer that describes making a $10 deposit is: Positive 10: +10
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