Shim's algebra question

It was during a particularly boring lecture that Shim slid a small piece of paper to Jaime and me, who sat right behind him. An algebra question was written on that piece of paper:

2xy = 10 + z
2x + y = 20
x = z + 10

What is y?

I just smiled. It was ages ago since I had done any math question of that nature. All those drillings I did to prepare for SPM has been forgotten. Yet, I was tempted to try my luck. Maybe the question's not so hard. There's no harm in trying is there?

Jaime, on the other hand, was more than gamed. She was really eager to attempt the question.

But before I started to pull a clean sheet of paper out, I asked Shim: "Betul ke soalan ni ada jawapan?"

He replied: "Mestila ade. Aku yang buat sendiri."

Hurm ... that's really promising (!). But I have faith in my friend. heh

Jaime and I tried and tried but we couldn't solve it. After sometime, Shim turned back to face us and said: "Eh, tak siap lagi ke?"

I gave up first. Jaime persisted for a while longer.

After she too had surrendered, Shim started working to give us the answer. I thought I would only take a while. But it took a lot longer than expected.

Jaime and I peeked over Shim's shoulder to see what he was doing. He seemed to be struggling with the question himself. We had to control our urge to laugh. From a small bit of paper that he was using, he had to pull out a larger piece to accommodate the more complex equations he's deriving.

Finally, he turned back once again, and slid us another note. It said:

"Soalan salah. muahaha"

It was a funny incident and it got me thinking about how bad I am in math. I used to be real good at it. But not anymore. My mental arithmetic is particularly embarassing. I guess that's one of the occupational hazards of being a TESL student. You deal with language, not numbers.

That's a pretty solid defence for my poor math ability don't you think?