Find the solution of given equations x + y = 100 and x + 2y = 150.

Given: 

x + y = 100 --- (1)

x + 2y = 150 -- (2)

Substract eq (2) from eq (1), We get:

$\Rightarrow$x + 2y - x - y = 150 - 100

$\Rightarrow$y = 50

Substitute value of y in eq (1), we get: 

$\Rightarrow$ x + y = 100

$\Rightarrow$ x + 50 = 100

$\Rightarrow$ x = 50

Therefore, x = 50 and y = 50