It looks like you already have a common denominator (y^2-9). So, you can just add the two numerators and put that over the common denominator. Hope this helps!
Answer:
see below
Step-by-step explanation:
amount of water w
l liter of pure alcohol = 100% alcohol
solution is 45 % percent alcohol
total amount of fluid is w+l
(w+l)( .45) = l*.100
Distribute
.45w + .45 l = 1l
.45 w = 1l - .45l
.45 w = .55l
w = .55l / .45
w =11/9 l
Answer:
-2 < w ≤ 6
Step-by-step explanation:
The inequalities you're asked to combine are ...
-2 < w
6 ≥ w
Turn one of these around so the "arrows" point in the same direction. (My preference is that they point to the left.) Now you have ...
-2 < w
w ≤ 6
You combine these by putting w in the middle:
-2 < w ≤ 6
_____
<em>Alternate solution</em>
I like the above solution because it puts the components of the expression in the same (left-right) order as they appear on a number line. However, both inequalities can be turned around to get ...
6 ≥ w > -2
I assume that the numbers are supposed to be written as 7.14 x 10^10 for December and 3.21 x 10^10. The total mail delivered is the sum of these two numbers.
(7.14 x 10^10) + (3.21 x 10^10) = 1.035 x 10^11
A(x - x₁)(x - x₂) = 0
a=5, x₁=-3, x₂ = 3
so:
5(x-(-3))(x-3)=0
5(x+3)(x-3)=0
5(x²-9) = 0
5x² - 45 = 0 ← answer
