x - 2y + z = 5 | *2
⇒ 2x - 4y+ 2z=10
3x + 3y - 2z = - 6 } I sum up these relations
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2x+3x - 4y+3y+2z-2z=10-6
5x - y = 4 (1)
3x + 3y - 2z = - 6 | *3 ⇒ 9x + 9y - 6z = - 18
2x - y + 3z = 11 | *2 ⇒ 4x - 2y + 6z= 22 I sum up these
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⇒ 9x+4x+9y-2y-6z+6z= 4
13x+ 7y= 4 (2)
I write (1) and (2)
5x - y = 4 | *7
35x - 7y= 28
13x+7y=4
48x = 32
x= 32/48=4/6 ( 32:8=4, 48:8=6)
x= 2/3
5x-y=4,
5*2/3-y=4
y=10/3 -4=10/3-12/3=-2/3
⇒ y= - 2/3
x - 2y + z = 5
2/3 - 2*(-2/3)+z=5
2/3+4/3+z=5
6/3+z=5
2+z=5
z=3
x+y+z=2/3-2/3+3=3
x+y+z=3
Study the function properly
Answer:
If you mean only one rational solution, the answer is
If you mean at least 1 rational solution, the answer is
![k\in (-\infty, -8]\cup[8, \infty)](https://tex.z-dn.net/?f=k%5Cin%20%28-%5Cinfty%2C%20-8%5D%5Ccup%5B8%2C%20%5Cinfty%29)
Step-by-step explanation:
Let's calculate the discriminant.
Now, remember that:
Therefore, I will just consider the first two cases.
and
I beleive the answer is 16
Take the square root. The opposite of squaring something is taking the root :)
√x^2 = √26
x = √26
x = 5.099...
OR leave it if your teacher doesn't want a decimal since it can't be simplified anymore
