4x-7x= 13
⇒ -3x= 13
⇒ x= 13/(-3)
⇒ x= -13/3
The final answer is x= -13/3~
        
             
        
        
        
Answer:
<h3>

</h3>
Step-by-step explanation:



 ?
?
Now, Using Pythagoras theorem

plug the values
⇒
Evaluate the power
⇒
Swap the sides of the equation
⇒
Move constant to right hand side and change it's sign
⇒
Calculate the difference
⇒
Squaring on both sides
⇒
Hope I helped!
Best regards!
 
        
             
        
        
        
Answer:

Step-by-step explanation:
Hello!
A trinomial is a expression consisting of three different terms
To turn this into a trinomial we multiply everything to each other
<u>                     3x                     </u>
3x * x = 
3x * 10 = 30x
<u>                     8                      </u>
8 * x = 8x
8 * 10 = 80
Now we put them all together in an equation

Combine like terms

The answer is 
Hope this helps!
 
        
             
        
        
        
Answer:20.571
Step-by-step explanation:
x:y = 21: 24=7:8
8x=7y
y=8x/7
When x=18
y=8*18/7
y=20.571