5000x+2000y+2400z= 129000
500 x+ 160y+300 z = 12900
x+y+z=40? Solve ternary linear equation
X = 15, Y = 15 and Z = 10 are obtained.
(2) I don't know if your second question is wrong. There are many answers, 1 TV, 1 washing machine, 2 air conditioning, and many schemes. 1, 1, 1,。 1,1,2 ...1,1,3 ... 2, 2,1... etc.