Http://mrdealy.weebly.com/uploads/2/3/5/2/23520438/geom._ch._3_angle_diagrams__3.8_worksheet.pdf
<em>Note: I am assuming the first equation is:</em>
<em>x+y = 3</em>
Answer:
The solution to the system of equations is:
(x, y) = (-2, 36)
Therefore, the x-coordinate of the solution of the system
x = -2
Step-by-step explanation:
Given the system of equations

subtracting the equations




solve -2y for y

Divide both sides by -2


For x+y=34 plug in y = 36

Subtract 36 from both sides

Simplify

Thus, the solution to the system of equations is:
(x, y) = (-2, 36)
Therefore, the x-coordinate of the solution of the system
x = -2
Answer:
A=12
B=54
C=18
Step-by-step explanation:
A=first
B=second
C=third
A+B+C=84
B=3C
A=C-6
C-6+3C+C=84
5C-6=84
5C=90
C=18
A=C-6
=(18)-6
=12
B=3C
=3(18)
=54
Looks like the system is
x + 4y - z = -14
5x + 6y + 3z = 4
-2x + 7y + 2z = -17
or in matrix form,

Cramer's rule says that

where
is the solution for i-th variable, and
is a modified version of
with its i-th column replaced by
.
We have 4 determinants to compute. I'll show the work for det(A) using a cofactor expansion along the first row.




The modified matrices and their determinants are



Then by Cramer's rule, the solution to the system is


