Value of x is used to consider unknown value. The letter “x” is commonly used in algebra to indicate an unknown value. It is referred to as a “variable” or, in some cases, a “unknown.” In x + 2 = 7, x is a variable
This an { } solution because the absolute value is always a positive number unless there is a negative sign in front of the brackets.
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Class 2 scored better on average
<h3>How to determine which class scored better on average?</h3>
The averages and the standard deviations are given as:
Class 1
Mean score = 7.8
Standard deviation = 1
Class 2
Mean score = 8.1
Standard deviation = 0.2
As a general rule, the smaller the standard deviation; the better the average
Class 2 has a smaller deviation
Hence, class 2 scored better on average
Read more about standard deviation at:
brainly.com/question/28061243
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Answer:
for quadratic equation 1
y^2-10y+21=0
Step-by-step explanation:
y^2-7y-3y+21=0
y(y-7)-3(y-7)=0
(y-7)(y-3)=0
y-7=0,y-3=0
y=7,y=3
y=(3,7)
for quadratic equation 2
16p^2-8p+1=0
16p^2-4p-4p+1=0
4p(4p-1)-1(4p-1)=0
(4p-1)twice=0
4p-1=0,4p-1=0
4p=1
p=1/4 twice
for quadratic equation 3
x^2-400=0
x^2=400
x=√400
x=20
for quadratic equation 4
-16m^2-8m-1=0
multiply the equation by -
16m^2+8m+1=0
16m^2+4m+4m+1=0
4m(4m+1)1(4m+1)=0
4m+1=0 twice
m=-1/4 twice
for quadratic equation 5
-3n^2+75=0
divide both side by -3
-3n^2/-3=-75/-3
n^2=25
n=√25
n=5