Answer:
Step-by-step explanation:
y= 40x + 50
y= 35x + 100
y= 40x + 50 = 35x + 100
40x - 35x = 100 - 50
5x = 50
x = 50/5
x = 10
y = 40 * 10 + 50 = 450
so the first answer is the correct one
