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Tardigrade
Question
Mathematics
If a point P (α, β, γ) satisfying (α β γ) beginpmatrix 2 10 8 9 3 8 8 4 8 endpmatrix=(0 0 0) lies on the plane 2 x+4 y+3 z=5, then 6 α+9 β+7 γ is equal to :
Q. If a point
P
(
α
,
β
,
γ
)
satisfying
(
α
β
γ
)
⎝
⎛
2
9
8
10
3
4
8
8
8
⎠
⎞
=
(
0
0
0
)
lies on the plane
2
x
+
4
y
+
3
z
=
5
, then
6
α
+
9
β
+
7
γ
is equal to :
414
135
JEE Main
JEE Main 2023
Three Dimensional Geometry
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A
4
5
B
−
1
C
11
D
5
11
Solution:
2
α
+
4
β
+
3
γ
=
5
.........(1)
2
α
+
9
β
+
8
γ
=
0
.........(2)
10
α
+
3
β
+
4
γ
=
0
.........(3)
8
α
+
8
β
+
8
γ
=
0
.........(4)
Subtract (4) from (2)
−
6
α
+
β
=
0
β
=
6
α
.........(5)
From equation (4)
8
α
+
48
α
+
8
γ
=
0
γ
=
−
7
α
.........(6)
From equation (1)
2
α
+
24
α
−
21
α
=
5
5
α
=
5
α
=
1
β
=
+
6
,
γ
=
−
7
∴
6
α
+
9
β
+
7
γ
=
6
+
54
−
49
=
11