<PRE><B>Question 1118569</B>
add equations 1 and 2 together
:
6x = 18
:
x = 3
:
substitute for x in equations 2 and 3
:
(2) 6 -y -2z = -6
:
(3) -3 +2y -z = -4
:
solve equation 2 for y
:
y = 12 -2z
:
substitute for y in equation 3
:

:
-3 +2(12-2z) -z = -4
:
24 -4z -z = -1
:
-5z = -25
:
z = 5
:
substitute for x and z in equation 1
:
4(3) +y + 2(5) = 24
:
12 +y +10 = 24
:
y = 2
:
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x = 3, y = 2, z = 5
:
check the answer
:
equation 1
:
4(3) +2 +2(5) = 24
:
12 +2 + 10 = 24
:
24 = 24
:
equation 2
:
2(3) -2 -2(5) = -6
:
6 -2 -10 = -6
:
-6 = -6
:
equation 3
:
-3 +2(2) -5 = -4
:
-3 +4 -5 = -4
:
-4 = -4
:
answer checks
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