X + y = 15
Rearrange this to isolate for x.
x = 15 - y
x + z = 20
Rearrange this to isolate for x also.
x = 20 - z
Since they are both equal to x, that means they are equal to each other (x = x)
Set them equal to each other.
15 - y = 20 - z
Now, isolate for y.
y = 15 - 20 + z
Now, use y + z = 25 and isolate for y.
y = 25 - z
Since they are both equal to y, we set them equal to each other.
15 - 20 + z = 25 - z
Solve for z
z + z = 25 - 15 + 20
2z = 30
2z/2 = 30/z
z = 15
Now you can plug the value for z into the other equations to find y and x.
x + z = 20
x +15 = 20
x = 20-15
x = 5
y + z = 25
y + 15 = 25
y = 25 - 15
y = 10
Answer:
Step-by-step explanation:
From equations (1) & (2), we find:
6x - 8 = - 3x +10
Plug x = 2 in equation (1)
y = 6(2)-8 = 12-8 =4
So,

probability that a dessert sold at a certain cafe contains chocolate is 86%.
The probability that a dessert containing chocolate also contains nuts is 30%.
Find the probability that a dessert chosen at random contains nuts given that it contains chocolate
P(nuts given chocolate) = .30/.86 = .349 or 34
Answer:
The number is 8.
Step-by-step explanation:
Rewrite the word problem as an equation.
The sum of (we will be adding.), half of a number (we can use x, this will be written as x/2.) and double the number (this will be written as 2x) is 20.
To find the number, solve the equation.
x/2 + 2x = 20
Multiply both sides by 2.
x + 4x = 40
Combine terms.
5x = 40
Divide both sides.
x = 8.
50% because when you take out the first marble witch is probably blue since there are more blue you would have 2 blue and 2 green so the chance would be 50%