total number of cards: 12 + 27 + 91 = 130
total number of cards with a circle: 91
so you have a 91/130 probability which reduces to 7/10 probability
Answer:
We start with the equation:
A: 3*(x + 2) = 18
And we want to construct equation B:
B: X + 2 = 18
where I suppose that X is different than x.
Because in both equations the right side is the same thing, then the left side also should be the same thing, this means that:
3*(x + 2) = X + 2
Now we can isolate the variable x.
(x + 2) = (X + 2)/3
x = (X + 2)/3 - 2
Then we need to replace x by (X + 2)/3 - 2 in equation A, and we will get equation B.
Let's do it:
A: 3*(x + 2) = 18
Now we can replace x by = (X + 2)/3 - 2
3*( (X + 2)/3 - 2 + 2) = 18
3*( (X + 2)/3 ) = 18
3*(X + 2)/3 = 18
(X + 2) = 18
Which is equation B.
Since g(x) varies with x, therefore:
g(x) = k/x where k is a constant.
So, first we need to get k. We are given that g(x) = 0.2 when x = 0.1
Substitute with these values to get k as follows:
g(x) = k/x
0.2 = k/0.1
k = 0.2*0.1 = 0.02
Now, the equation became:
g(x) = 0.02 / x
We need to get the g(x) when x = 1.6
Therefore, we will substitute with x in the equation and calculate the corresponding g as follows:
g(x) = 0.02 / 1.6
g(x) = 0.0125
2x+y=9
3x+5y=19
I will do this problem in 2 ways. I.)Substitution II.)Elimination
Solution I.) Substitution
We can subtract 2x from both sides in the first equation.
y=9-2x
Now we can substitute the y in the second equation with 9-2x
3x+5(9-2x)=19
-7x+45=19
-7x=-26
x=26/7
y=9-2(26/7)=11/7
Solution II.)Elimination
We can multiply both side of first equation by 5 to get a 5y in both equations.
10x+5y=45
Now because both are positive 5y we just need to do simple subtraction of the 2 equation, each side respectively.
(10x+5y)-(3x+5y)=45-19
7x=26
x=26/7
2*26/7+y=9
y=11/7
Ultimately you get the same answer, both are viable methods, some problems are faster with one method but I recommend mastering both since they are very useful.
The answer is 10 because it had
