Answer:
(-6,9,-3)
Step-by-step explanation:
-3x -y +z=6
-3x-y+3z =0
x-3z =3
Multiply the second equation by -1
-1 *(-3x-y+3z) =0*-1
3x +y -3z =0
Add this to the first equation
-3x -y +z=6
3x +y -3z =0
----------------------
0 + 0 + -2z = 6
Divide by -2
-2z/-2 = 6/-2
z = 6/-2
z=-3
Take the third equation to find x
x-3z=3
x-3(-3) = 3
x+9=3
Subtract 9 from each side
x+9-9 =3-9
x=-6
Now we need to find y
3x +y -3z =0
3(-6) +y -3(-3) =0
-18 +y +9=0
-9+y =0
Add 9 to each side
-9+9+y = 0+9
y=9
(-6,9,-3)
Answer:
2.25 and 4.95
Step-by-step explanation:
x + y = 7.2
x - y = 2.7
x = 7.2 - y
x - y = 2.7
(7.2 - y) - y = 2.7
7.2 - 2y = 2.7
-2y = 2.7 - 7.2
-2y = -4.5
-2y/-2 = -4.5/-2
y = 2.25
x + y = 7.2
x + 2.25 = 7.2
x = 7.2 - 2.25
x = 4.95
Check: 4.95 and 2.25
x + y = 7.2
(4.95) + (2.25) = 7.2
7.2 = 7.2
x - y = 2.7
(4.95) - (2.25) = 2.7
2.7 = 2.7
X^2 + 8x + 7 = 0
x^2 + 7x + x + 7 = 0
x(x + 7) + 1(x + 7) = 0
(x + 7) (x + 1) = 0
x = -7 or x = -1
Answer:
The answer is option B.
Step-by-step explanation:
Hope this helps you
The answer I got was a=5. Hope this is correct and hope it helped
