X² - 4x - 77 = 0
( x + 7) ( x - 11) 
x + 7 = 0
x - 11 = 0
x = -7
x = 11
        
             
        
        
        
Answer:
7.5 L of 10% solution and 22.5 L of 30% solution
Step-by-step explanation:
Volume of 10% solution plus volume of 30% solution = total volume of 25% volume.
x + y = 30
Acid in 10% solution plus acid in 30% solution = total acid in 25% solution.
0.10 x + 0.30 y = 30 × 0.25
0.10 x + 0.30 y = 7.5
Solve the system of equations, using either substitution or elimination.  I'll use substitution:
x = 30 − y
0.10 (30 − y) + 0.30 y = 7.5
3 − 0.10 y + 0.30 y = 7.5
0.20 y = 4.5
y = 22.5
x = 30 − y
x = 7.5
Sarah needs 7.5 L of 10% solution and 22.5 L of 30% solution.
 
        
                    
             
        
        
        
Answer:
3.6
Step-by-step explanation:
Hi there!
We are given this expression:
.6√36 (.6*√36) 
And we want to find the value of it
.6 can be re-written as 0.6
In that case,
0.6*√36
First, simplify what's under the radical: √36, which is equal to 6 (6*6=36) 
The expression then becomes:
0.6*6
Multiply those numbers together
0.6*6=<u>3.6</u>
Hope this helps! 
 
        
             
        
        
        
What three cards I don’t see anything and this is just an statement
        
                    
             
        
        
        
Answer:
X=105
Step-by-step explanation:
5x-2=4x-103
Combine the like terms
5x-4x=103+2
X=105