A cow has two eyes and four legs, and a chicken has two eyes and two legs.

Total ***86 eyes 142 legs ~ ~

Let chicken x cow y be 2X+2Y=86 2X+4Y= 142.

X= 15 Y=28。

The second question:

Let the big iron weigh x kilograms and the small iron weigh y kilograms.

This sentence puts a big iron plate and a small iron plate on both sides of a lifting road weighing 6 kilograms. Now the total mass is 150kg.

Get 2X+2Y+6= 150.

Through this sentence, he added a small piece of iron on each side, and by then, its weight will be 202 kilograms.

Get 4X+2Y+6=202.

X=26 Y=46。

What's a little difficult? The problems that domestic primary school students do are more difficult than this ~ ~ ~

By the way, what does this word mean, yjis?