Given:
The system of equations:


To find:
The number that can be multiplied by the second equation to eliminate the x-variable when the equations are added together.
Solution:
We have,
...(i)
...(ii)
The coefficient of x in (i) and (ii) are 1 and
respectively.
To eliminate the variable x by adding the equations, we need the coefficients of x as the additive inverse of each other, i.e, a and -a So, a+(-a)=0.
It means, we have to convert
into -1. It is possible if we multiply the equation (ii) by -5.
On multiplying equation (ii) by -5, we get
...(iii)
On adding (i) and (iii), we get

Here, x is eliminated.
Therefore, the number -5 can be multiplied by the second equation to eliminate the x-variable.
<span>System 1 and system 2, because the second equation in system 2 is obtained by adding the first equation in system 1 to two times the second equation in system 1
This is the correct answer because not only is it true but it also follows the property of solving systems of equations with adding the equations. To prove that it is true:
2nd equation in system #2 = 1st equation in system #1 + 2(2nd equation in system #1)
</span>10x − 7y = 18 == 4x − 5y = 2 + 2(<span>3x − y = 8)
10x - 7y = 18 == 4x - 5y = 2 + 6x - 2y = 16
10x = 7y = 18 == 10x - 7y = 18</span>
The probability that a point is chosen at random in the square is in the blue region is 0.8.
<h3>What is Probability?</h3>
The probability helps us to know the chances of an event occurring.

As we know that the area of the shaded region is the sum of the area of triangle A and the area of triangle B. Therefore, the area of the blue shaded region is,


The area of the square can be written as,

Now, the probability that a point is chosen at random in the square is in the blue region can be written as,


Hence, the probability that a point is chosen at random in the square is in the blue region is 0.8.
Learn more about Probability:
brainly.com/question/795909
<span>t=10, so p(10)=430*1.009^10? hope this helps:)</span>