Answer:
a shs s s s ss bsbsbsbs s s s s s s s s s s s s s
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.
It’s 0.3 because that’s the answer
The probability that the sample mean is less than 30 school days will be given as follows:
the z-score is given by:
z=(x-μ)/σ
where
μ- stand deviation
σ-mean
thus the z-score of our information is:
z=(30-28)/9
z=0.222222
hence the probability that the sample mean is less than 30 will be:
P(x<30)=0.5871~58.71%
During its first bake sale, the poetry club made $79.35. If we round up to $80, this will make it easier to estimate how much they will make if they have 4 more bake sales (5 altogether). Next, we should use multiplication to determine how much money they will earn altogether after 5 bake sales. Five times $80 equals $400. Leslie accidentally multiplies by 50 because she moves the decimal one place too far.
<h3>Further Explanation</h3>
Estimation
Estimation is when you use an approximate calculation to make a prediction. It is important here to note that an estimation is different than guess. In both instances, one should use whatever knowledge is at their disposal; however, an estimation usually uses rounding and actual calculations.
Rounding
When making an estimation, rounding is an effective tool to use. Often numbers are rounded to the nearest whole number or place value. This can make it easier to do a quick calculation. In the word problem, the nearest whole number to 79.35 is 80. This makes it easier to multiply the dollar amount because there are fewer numbers to multiply.
<h3>Answer Details</h3>
Subject: Math
Level: middle school
Topic: Estimations
<h3>Keywords</h3>
estimation, rounding, multiplication
<h3>Learn More</h3>
Estimating with percents: brainly.com/question/3510011
Estimate: brainly.com/question/107747
