Answer:
#5 x=8, #6 x=5
Step-by-step explanation:
Theyre vertical so for number 5 you would have the equation
5x+15=55
     -15   -15 from both sides
5x=40
divide by 5 from both sides and you get
x=8 
Same thing vertical so you would have   
16x+7=87
     -7    -7 from both sides
16x=80
divide by 16 from both sides
x=5
 
        
             
        
        
        
Answer:
I'm newbie here 
Step-by-step explanation:
Elimination Method.
4x + 6/y = 15 → step 1 
6x - 8/y = 14 → step 2
so, 
4x + 6/y = 15 |×6| 
6x - 8/y = 14 |×4|
24x + 6/y(6) = 90
24x - 8/y(4) = 56
24x + 36/y = 90
24x - 32/y = 56
____________ _ 
 68/y = 34
 68 = 34y 
 34y = 68
 y = 2 
subsitution y = 2 to..
4x + 6/y = 15 
4x + 6/2 = 15 
4x + 3 = 15 
4x = 12
x = 3 
So, for x is 3, and for y is 2 
 
 
        
                    
             
        
        
        
Answer:
B
Step-by-step explanation:
In a triangle, the sum of any two sides must be bigger than the third.
For the first one, 10+20=30 is not greater than 30, so this is not correct.
For B, 122+137 = 259 > 257, 257+137>122  , and 257 + 122 > 137. This works
For C, 8.6 + 2.7 = 11.3 < 12.2, so this does not work
For D, 1/6 + 1/5 = 5/(6*5) + 6/(6*5) = 5/30 + 6/30 = 11/30 < 1/2 = 15/30, so this does not work
 
        
             
        
        
        
Pounds: 10  20  30
Kilos:      4.5   9  13.5
half of 20 is 10, and half of 9 is 4.5.  So every 10 pounds is 4.5 kilos.  Add 10 to 20 to get 30, and add 4.5 to 9 to get 13.5.  Both parts of the ratio table are increasing at the same rate (either 10 eachtime or 4.5 each time).  
        
             
        
        
        
well, let's notice something, we have two 45° angles, now each of those will give use an equal opposite side, namely if that one side is "x", the other is her twin, "x" as well.
is a right-triangle, so we can use the pythagorean theorem, and we know the sides are x,x,6.
