Hi I did my working on paper. You can see it in the photo.
Answer:
{x=2,y=2
Step-by-step explanation:
Equation 1:
Multiply both sides of the equation by a coefficient
{ 4(2x-y)=2*4
-5x+4y=-2
Apply Multiplicative Distribution Law
{8x-4y=2*4,-5x+4y=-2
8x-4y+(-5x+4y)=8+(-2)
Remove parentheses
8x-4y-5x+4y=8-2
Cancel one variable
8x-5x=8-2
Combine like terms
3x=8-2
Calculate the sum or difference
3x=6
Divide both sides of the equation by the coefficient of the variable
x=6/3
Calculate the product or quotient
x=2
Equation two:
{-5+4y=-2, x=2
-5*2+4y=-2
Calculate the product or quotient
-10+4y =-2
Reduce the greatest common factor (GCF) on both sides of the equation
-5+2y=-1
Rearrange unknown terms to the left side of the equation
2y=-1+5
Calculate the sum or difference
2y=4
Divide both sides of the equation by the coefficient of the variable
y=4/2
y=2
Hope this helps!!
Answer:
a

b

Step-by-step explanation:
From the question we are told that
The mean value is 
The standard deviation is 
Considering question a
The sample size is n = 9
Generally the standard error of the mean is mathematically represented as

=>
=> 
Generally the probability that the sample mean hardness for a random sample of 9 pins is at least 51 is mathematically represented as



=> 
From the z table the area under the normal curve to the left corresponding to 2.5 is

=> 
=> 
Considering question b
The sample size is n = 40
Generally the standard error of the mean is mathematically represented as

=>
=> 
Generally the (approximate) probability that the sample mean hardness for a random sample of 40 pins is at least 51 is mathematically represented as

=> 
=> 
From the z table the area under the normal curve to the left corresponding to 5.2715 and
=> 
So

=> 
Answer:
req grade=35%
Step-by-step explanation:
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req grade=35% answer
An algebraic expression consists of one or more numbers and variables, for 1/8y it will be y+1/8