Cramer's rule works as follows:
x+3y=16
3x+y=8
Then
x=Dx/D
y=Dy/D
where Dx,Dy,D are 2x2 matrices formed from of coefficients and right hand side.
D=
1 3
3 1
=1-9=-8
Dx=matrix D with first column replaced by the vector [16,8]=
16,3
8 1
=16-24
=-8
Dy=matrix D with second column replaced by the vector [16,8]=
1 16
3 8
=8-48
=-40
Therefore
x=-8/-8=1
y=--40/-8=5
Check:
x+3y=1+3(5)=16
3x+y=3(1)+5=8 ok.
B=90
I think this is the answer
To find the unit rate, we need to set the number of days to 1. Therefore, we will divide by 7. We also have to divide 42 by 7 to make sure the equation stays proportional. Using this knowledge, we can see that if the corn grew 42 inches in 7 days, it grows 6 inches per day.
Answer:
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