Answer:
huh thanks for the points ig :)
Step-by-step explanation:
 
        
             
        
        
        
Two is equivalent to twenty and 84
        
                    
             
        
        
        
Answer:
x=3, y= -6
Step-by-step explanation:
make 4+y= -x as equation (1) and make y=2x-10 as equation (2, then you must find a third equation either from equation (1)or (2). If you choose to find equation (3) from (2) it will be y=2x-10 , then substitute equation (3) from (1) because you can't choose (2) , then it will be 4+(2x-10)= -x 
the answer will be x =2
substitute x from equation (3)
y=2x-10
y=2 (2)-10
y= -6
 
        
             
        
        
        
Answer:
13
Step-by-step explanation:
 
        
             
        
        
        
Answer:
60 maths books
Step-by-step explanation:
<u>Let the following be:</u>
- Maths books = m
- Science books = s
- History books = h
<u>And we have ratios and sum:</u>
- m/s = 3/2
- s/h = 1/3
- m+s+h = 220
<u>From the ratios we get:</u>
<u>Considering the above in the sum of books:</u>
- m+s+h = 220
- 3s/2 + s + 3s = 220
- 3s + 2s + 6s = 2*220
- 11s = 440
- s = 440/11
- s = 40
<u>Number of maths books:</u>