Pls mark me as the Brainliest as I really need it, thanks!
Answer:
B and B
Step-by-step explanation:
The first one is B because all of the slopes are negative except B. And so I think that's the correct answer
The second one I know is B for sure, I remember learning it in 8th grade 2 years ago.
It's really just the first one I am second guessing myself on but B and B make sense to me :)
Answer:
4KO2 + 2CO2 → 2K2CO3 + 3O2
Step-by-step explanation:
First we write the reaction in the asked form :
x1 KO2 + x2 CO2 → x3 K2CO3 + x4 O2
In a chemical equation, tha amount of substance that react is the same amount that is formed :
On each side of the equation we must have the same amount of K,C and O.
Let's write this in equations :
K balance :
C balance :
O balance :
The linear equations system is :
Let's equal to 0 to obtain a homogeneous equations system (for convenience) :
Let's work with the extended system matrix :
Working with the matrix :
→
→
→
→
→
The matrix is extended to the following linear system :
t∈ IR
Let's choose t=3 to eliminate the fractional numbers →
Answer:
<u>475 runners</u> competed in the Labor Day race.
Step-by-step explanation:
Given:
Last year, 60% of runners who competed in the Labor Day race finished in 1 hour or less. There were 285 runners who finished the Labor Day race in 1 hour or less.
Now, to find the runners competed in the Labor Day race.
Let the runners competed in the Labor Day race be
Rate of runners who competed in the Labor Day race finished in 1 hour or less = 60%.
Number of runners who competed in the Labor Day race finished in 1 hour or less = 285.
Now, to get the runners competed in the Labor Day race we put an equation:
<em>Dividing both sides by 0.60 we get:</em>
Therefore, 475 runners competed in the Labor Day race.
Answer:
Step-by-step explanation:
the first one