The solution to the systems of equations is (7, 3)
Given the systems of equations expressed as:
-x + 4y = 5 ....................1
x - 5y = -2 ...................... 2
Add both equations to have:
-x+x + 4y - 5y = 5 - 2
4y-5y = -3
-y = -3
y = 3
Substitute y = 3 into equation 1:
-x + 4(3) = 5
-x + 12 = 5
-x = 5 - 12
-x = -7
x = 7
Hence the solution to the systems of equations is (7, 3)
Learn more on simultaneous equations here: brainly.com/question/148035
We want to find the mean of two elements in a set, given that we know the other elements of the set and the mean of the whole set.
The answer is: -490
-----------------------------
For a set with N elements {x₁, x₂, ..., xₙ} the mean is given by:
Here we know that:
- The mean of the set is 0.
- The set has 1000 elements.
- 998 of these elements are ones, the other two are A and B.
We want to find the mean of the values of A and B.
First, we can start by writing the equation for the mean:
We can rewrite this as:
And we have 998 ones, then:
Now we have B isolated.
With this, the mean of A and B can be written as:
So we can conclude that the mean of the other two numbers is -490.
If you want to learn more, you can read:
brainly.com/question/22871228
Answer:
Step-by-step explanation:
The LCM of 14, 21 and 6 is 42
We require to change the fractions to fractions with a denominator of 42
+ +
= + + ← add the numerators, leaving the denominator
=
= ← divide both values by 2
= ← in simplest form
24% = 24/100 = 12/50 = 6/25
24% is 6/25 fraction of world's energy.