A. x=1, y=3
Step-by-step explanation:
2x+y= 5
2(1) + 3 = 5
2+3=5
x+y=4
1+3=4
f(x) has value 150 at x= 0
and 0 at x= 3
so d(f(x))/dt = slope = -150/3 = -50