tres cajas contienen cuatrocientas naranjas la primera tiene veinte naranjas mas q la segunda y treinta mas q la tercera cuantas naranjas hay en cada caja

Answer: Box3 has 120 oranges.

Box1 has 150 oranges.

Box has 130 oranges.

Step-by-step explanation:

I will answer this in English.

The question says:

3 boxes have 400 oranges.

The first one has 20 more than the second and 30 more than the third.

So we have 3 equations:

box1 + box2 + box3 = 400

box1 = box2 + 20

box1 = box3 + 30

Now, we can take the variable box1 in the third equation and replace it on the other two.

box3 + 30 + box2 + box3 = 400

box3 + 30 = box2 + 20

Now we can isolate one of the variables in the second equation, let's isolate box2.

box2 = box3 + 30 - 20 = box3 + 10

now we can replace it in the other equation:

box3 + 30 + box2 + box3 = 400

box3 + 30 + box3 + 10 + box3 = 400

3*box3 + 40 = 400

3*box3 = 400 - 40 = 360

box3 = 360/3 = 120.

Box3 has 120 oranges.

Box1 has 120 + 30 = 150 oranges.

Box has 150 - 20 = 130 oranges.