Nataliya D. answered • 12/01/13

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(1.) If a horse will give to a donkey 1 bale, then a horse will be carrying (y - 1) bales and a donkey will be carrying (x + 1) bales, which will be half as much as horse's.

So, we can write first equation:

1

x + 1 = ---(y - 1)

2

(2.) From other side, if a donkey will give 1 bale to a horse, then a donkey will be carrying (x - 1) bales and a horse will be carrying (y + 1) bales, which is 3 times as much as donkey's.

Thereby, we can write second equation:

y + 1 = 3(x - 1)

Now, let's solve system of two equations:

x + 1 = 0.5(y - 1)

y + 1 = 3(x - 1)

Let's open parentheses and move all variables on the left side of each equation and numbers on the right side:

x + 1 = 0.5y - 0.5

y + 1 = 3x - 3

x - 0.5y = - 1 - 0.5

-3x + y = - 1 - 3

2x - y = -3

+

- 3x + y = - 4

---------------------

- x = - 7

x = 7

Let's plug in the value of "x" into

**equation**

*second original*y + 1 = 3(7 - 1)

y = 18 - 1 = 17

*Originally, a donkey was carrying 7 bales and a horse was carrying 17 bales.*