Question

One says,"give me a hundred,friend! I shallthen become twice as rich as you".The other replies,"If you give me ten,I shall be as rich as you".Tell me what is the amount of their(respective)capital?

Answer 1

Let,
the capital of first man =x
the capital of second man=y.

"give me a hundred,friend! I shallthen become twice as rich as you".

It means,
x+100 = 2y

Rearrange the equation.

x-2y =-100
multiply both side by (-1)
2y-x =100 ---------(1)

"If you give me ten,I shall be as rich as you".

It means,

​​y+10 = x
Rearrange the equation

y-x = -10 ----------(2)


Now, we should solve these 2 equations.
So, subtract (2) from(1).

(2y-x)-(y-x) =(100)-(-10)
y-x+x = 110
y=110
x=-10+y = -10+110=100

x=100 y=110 are the capitals