Let's say we use "x" of the 25% OJ... ok... well, how much juice is really in that "x" liters? well, 25% of it is OJ, the rest is water, how much is 25% of x? well, (25/100) * x, or 0.25x.
likewise, we'll use "y" of the 10% OJ, and it will end up with (10/100) *y or 0.10y of juice in it.
whatever "x" and "y" are, they must add up to 15 Liters, and the juice concentration on that mixture, must also be the sum of their sum concentration.

how much will be it of the 10% juice? well, y = 15 - x.
Answer: 5:6
Explanation:
The 2 polygons are similar
So 25/30 = 25.5/30.6 = 5/6 or 5:6
Answer:
and
.
Step-by-step explanation:
So I believe the problem is this:

where we are asked to find values for
and
such that the equation holds for any
in the equation's domain.
So I'm actually going to get rid of any domain restrictions by multiplying both sides by (x-3)(x+7).
In other words this will clear the fractions.


As you can see there was some cancellation.
I'm going to plug in -7 for x because x+7 becomes 0 then.




Divide both sides by -10:


Now we have:
with 
I notice that x-3 is 0 when x=3. So I'm going to replace x with 3.




Divide both sides by 10:


So
and
.
Answer:
no solutions
Step-by-step explanation:
y = -3x +10
3x +y = 5
Substitute the first equation into the second equation
Let every instance of y in the second equation be replaced with -3x+10
3x+ (-3x+10) = 5
Combine like terms
10 =5
This is never true so there are no solutions
(These are parallel lines with the same slope but different y intercepts)
7) 2-3=-1 9) 6-9=-3
11) -3-4=-7 13) -7-6=-13
15)-3-9=-12 17) 6-(-2)=8
19)3-(-5)=8 21) 5-(-8)=13
23)-2-(-1)=-1 25) -10-(-4)=-6
27)-6-(-5)=-1 29) -8-(-6)=-2
31)5-(-3)=8 33) 7-10=-3
35)-2-5=-7 37) -9-(-4)=-5