Answer:
Step-by-step explanation:
given is a system of linear equations in 3 variables as

This can be represented in matrix form as
AX=B Or
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So solution set
X would be 
|A|=-1(-1)+4(0)+2(-1)=--1
Cofactors of A are
-1 0 -1
-2 -1 -3
0 1 2
So inverse of A is
1 2 0
0 1 -1
1 3 -2
Solution set would be
x=12
y=-3
z=-5
1) 13a=-5
Make a the subject of the formula by dividing both sides by 13(the coefficient of a)
13a/13=-5/13
Therefore a= -0.385
The second one). 12-b= 12.5
You take the 12 to the other side making b subject of the formula (-b in this case)
-b= 12.5-12
-b= 0.5
(You cannot leave b with a negative sign so you will divide both sides by -1 to cancel out the negative sign)
-b/-1= 0.5/-1
Therefore b=-0.5
The third one). -0.1= -10c
You will divide both sides by the coefficient of c(number next to c) which is -10
-0.1/-10= -10c/-10
Hence, c= 0.01
Step-by-step explanation:
y = ax^n + bx^(n-1) ... + z
(0, 1) tells us that the constant term z = 1.
because x = 0 eliminates all other terms. and as the sum is 1, that means z = 1.
for the other pairs I strongly suspect
(-1, 3) : 2×(-1)² + 1 = 2×1 + 1 = 3
(-2, 9) : 2×(-2)² + 1 = 2×4 + 1 = 9
so, the fitting equation is
y = 2x² + 1
Answer: (22) $9,075 (23) $656.25 (24) $217.13
<u>Step-by-step explanation:</u>
Cost Function: C(x) = 5.75x + 8,000
C(10,000) = 5.75(10,000) + 8,000
= 57,500 + 8,000
= 65,500
Revenue Function: R(x) = 9.50x
R(7,850) = 9.50(7,850)
= 74,575
Profit Function: P(x) = R(x) - C(x)
= 74,575 - 65,500
= 9,075
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Retail = Unit Cost + Unit Cost × Markup
= $375 + $375 × .75
= $375 + $281.25
= $656.25
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$225 but if paid within 10 days there is a 3.5% discount
Discount = $225 - $225 × .035
= $225 - $7.88
= $217.13