Solution: Let's have a triple room X and a double room Y.

3x+2y=50 ①

75x+70y= 15 10 ②

From (1),

y=25- 1.5x ③

Incorporate ③ into ②

75x+70(25- 1.5x)= 15 10

75x+ 1750- 105 x = 15 10

-30x=-240

x=8

Substitute x=8 into ③ and y= 13.

The solution of the original equation is x=8 y= 13.

Hope to adopt, typing is very tiring ~