Question 901429
x+y=400,
48*x+36*y=18600
x=400-y
48*(400-y)+36*y=18600
19200-48y+36*y=18600
-12*y=-600
y=50 at $36
x=400-y
x=350 at $8
check
48*350+036*50=18600
16800+1800=18600
18600=18600
ok