Chickens and rabbits in the same cage, rabbits less than 20 chickens, a total of 262 feet, how many chickens and rabbits each ? Process, formula, equation can also oh ~ but not binary linear equation~

Suppose there are x rabbits and X + 20 chickens
Then 4x + 2 * (x + 20) = 262
6x=222
x=37
There are 37 rabbits and 57 chickens

It is known that the number of rabbits is 6 times that of chickens. There are 390 feet in chickens and rabbits. How many are each?

Suppose there are x chickens, then there are 6x rabbits
2x+4*6x=390
That is: 26x = 390
So x = 15, 6x = 90
There are 15 chickens and 90 rabbits

There were x chickens and 30-x rabbits
4（30－X）－2X＝24
120－4X－2X＝24
120－6X＝24
6X＝120－24
6X＝96
X＝96/6
X＝16
30－16＝14
A: 16 chickens and 14 rabbits