I think it's 0.385. I might be wrong. Try using WolframAlpha for this stuff, it should work.
Answer:
y= -1/4x
Step-by-step explanation:
Answer:
D. 80 mph
Step-by-step explanation:
d- distance
- d/50= 0.6d/40+0.4d/x
- 1/50= 0.3/20+0.4/x
- 0.4/x= 0.02- 0.015
- x= 0.4/0.005
- x= 80 mph
Add 21 to both sides, so you get 9z = 81