Answer:
3:7
Step-by-step explanation:
So to solve this problem, you have to understand what the ratio 1:4 and 2:3 means. The 1:4 ratio in the first equation means that for "each unit of alcohol" there is 4 of those units of water. So let's say I had 2 gallons of alcohol and mixed it with 8 gallons of water. This means for each gallon of alcohol, there is 4 gallons of water, or in other words a 1:4 ratio. This can be described as a percentage as well. For each 5 gallons there are 4 gallons of water, and 1 gallon of alcohol or <em>20%</em> is alcohol. So let's just say that x=alcohol and y=water, this means that: 
where c is the total amount in the glass. This means that: 
Let's do the same thing to the second equation. the ratio means that for every 2 units of alcohol there are 3 units of water. This means for every 5 gallons of the mixture there is 2 units of alcohol which is 40%. In this case let's also say that j=alcohol and k=water. This means that: 
and that: 
.
So if we're going to add the two glasses, we simply add the two sides, and get: 
. Now remember how can can express j and x in terms of c, since it's a certain percentage of c (the entire thing). This means that we get: 
Now we can add like terms to get the equation: 
. We can find how much 0.6c is to 2c by dividing the 2, in doing so we get that 0.6c/2c = 0.3, or in other words the 0.6c is only 30% of the final mixture, and since the 0.6c represents the alcohol in this mixture, that means that's the percentage of alcohol. To write this as a ratio, this means for every 3 units of alcohol, there is 7 units of water, because 3/10 = 30%.
Answer:
Option C.
Step-by-step explanation:
The general exponential equation is
It is given that the graph of exponential function passes through points (4,8) and (6,32). It means the equation of exponential function must be satisfied by these points.
...(1)
...(2)
Divide equation (2) by equation (1).
Taking square root on both sides.
Put b=2 in (1).
Substitute a=0.5 and b=2 in the given general exponential equation.
Therefore, the correct option is C.
Answer:
solution given;
let
AB=a
AC=b=30ft
AB=c=20ft
<A=115°
By using Cosine rule.
a²=b²+c²-2bc cos angle
a²=30²+20²-2*30*20 Cos 115°
a²=1807.1419
a=√[1807.1419]
a=42.51
Side A is 42.51ft.
Again
Cos B=
Cos B=
Cos B=0.7687
<B=Cos -¹(0.7687)
<B=39.46°
Angle B is 39.46
Reta a:
reta x:
Retas paralelas possuem coeficientes angulares iguais ⇒ mₐ=mₓ
(-4,-2)
∴
y=3/4x+1
Suppose in 1992 Chris was x years old, his brother was then 2x years old.
6 years later in 1998, Chris is (x+6) years old, his brother is (2x+6),
(x+6)=(2/3)(2x+6)
x+6=(4/3)x+4
(4/3)x-x=6-4
(1/3)x=3
x=6
in 1992, Chris was 6, so in 2018 he will be 6+(2018-1992)=32 years old.
