Answer:
(6,3,0)
Step-by-step explanation:
Given,
x - y + 0z = 3
6x - 0y - 2z = 36
0x + 6y + 2z = 18
You have the following augmented matrix:
(1) 1 -1 0 3
(2) 6 0 -2 36
(3) 0 6 2 18
Let's (3) add to (2) and divide by 6
(1) 1 -1 0 3
(2) 1 1 0 9
(3) 0 6 2 18
Now, let's (2) add to (1) and divide by 2
(1) 1 0 0 6
(2) 1 1 0 9
(3) 0 6 2 18
Let's (3) ÷ 2
(1) 1 0 0 6
(2) 1 1 0 9
(3) 0 3 1 9
Let's (1) subtract from (2)
(1) 1 0 0 6
(2) 0 1 0 3
(3) 0 3 1 9
Finally, let's (2) multiply by 3 and subtract from (3)
(1) 1 0 0 6
(2) 0 1 0 3
(3) 0 0 1 0
Thus,
x = 6, y = 3 and z = 0
The answer is (6, 3, 0)
We have to verify the answer
6 - 3 = 3 ⇒⇒ 3 = 3
6*6 - 5*0 = 36 ⇒⇒ 36 = 36
6*3 + 2*0 = 18 ⇒⇒ 18 = 18
X= -2 and x= 2 are the answers
For the first one it is -8>24 that statement is false
For the second one it is x>-4
Answer:
A.
Step-by-step explanation:
you have to find the discriminant
b²-4ac for each equation
if discriminant < 0 no real solutions because will be negative under the squareroot whhan you try to find the roots
if discriminant = 0 there is only one solution
if discriminant > 0 two real solutions
for your given problems
A. discriminant =(-2)²-4*2*15 will be negative
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