# Thread: Elimination Homework: Help for 2 Questions

1. ## Elimination Homework: Help for 2 Questions

I'm brand new here. I've been having a little bit of trouble with this homework I have here. Using Elimination for 11 problems; I'm pretty bad at this for some reason. Substitution was a breeze, but this isn't working for me. I'm only a freshman, so this may be a little easier for you guys lol. Here they are.

Five hundred gallons of 82-Octane gasoline is obtained by mixing 80 octane gasoline and 86 octane gasoline. How much of each is used?

All I need is a second equation. So far I have 500 = 80 + 86 (Unsure if correct)

A van travels for two hours at an average speed of 40 mph. For how long must the van then travel at 55 mph to raise the overall average to 45 mph? What is the total time traveled?

Thanks all!

2. Originally Posted by BakedZombie
I'm brand new here. I've been having a little bit of trouble with this homework I have here. Using Elimination for 11 problems; I'm pretty bad at this for some reason. Substitution was a breeze, but this isn't working for me.
If you can't show more work than you did, then this has nothing to do with elimination and/or substitution!

Here's a hint on each:
Code:
     x @ 80
500-x @ 86
==========
500 @ 82

@40mph.....[80 miles].....>[2 hours]@55mph....[55x miles].....>[x hours]
Sorry, but we do not do homework here; site rules.