The answer should be 21 hope it helps
        
                    
             
        
        
        
Answer:
B) (-10, -6) and (8, -6) 
Step-by-step explanation:
 
        
                    
             
        
        
        
Last option is the correct answer.
Step-by-step explanation:
Given that
Let x stand for the solution a and y stand for the solution B
So,
According to statement that
30 gallons have to be made

Solution A contains 29 percent bromine => 0.29x
Solution B contains 53 percent  =>0.53y
And the mixture of 30 gallons contains 45% bromine

Following equations will be used for solving the problem

Hence,
Last option is the correct answer.
Keywords: Equations, Variables
Learn more about linear equations at:
#LearnwithBrainly
 
        
             
        
        
        
Answer:
You are given:
4Fe+3O_2 -> 2Fe_2O_3
4:Fe:4
6:O_2:6
You actually have the same number of Fe on both sides, The same is true for O_2 so yes this equation is properly balanced.
For added benefit consider the following equation:
CH_4+O_2-> CO_2+2H_2O
ASK: Is this equation balanced? Quick answer: No
ASK: So how do we know and how do we then balance it?
DO: Count the number of each atom type you have on each side of the equation:
1:C:1
4:H:4
2:O:4
As you can see everything is balanced except for O To balance O we can simply add a coefficient of 2 in front of O_2 on the left side which would result in 4 O atoms:
CH_4+color(red)(2)O_2-> CO_2+2H_2O
1:C:1
4:H:4
4:O:4
Everything is now balanced.
Step-by-step explanation: