2x + y - Bz
1. If
х
2y
find the value of z when x = 1 and y = 4.
y + 3x
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Answers
Answered by
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3x−4y+7z=0.....(i)
2x−y−2z=0......(ii)
3x
3
−y
3
−z
3
=8....(iii)
Applying cross multiplication on (i) and (ii)
8+7
x
=
−6−14
−y
=
−3+8
z
15
x
=
20
y
=
5
z
3
x
=
4
y
=z=k
⇒x=3k,y=4k,z=k
Substituting x,y and z in (iii)
⇒x=3k,y=4k,z=k
3(3k)
3
−(4k)
3
+(k)
3
=8
k
3
=1
k=1
⇒x=3,y=4,z=1
2x−y−2z=0......(ii)
3x
3
−y
3
−z
3
=8....(iii)
Applying cross multiplication on (i) and (ii)
8+7
x
=
−6−14
−y
=
−3+8
z
15
x
=
20
y
=
5
z
3
x
=
4
y
=z=k
⇒x=3k,y=4k,z=k
Substituting x,y and z in (iii)
⇒x=3k,y=4k,z=k
3(3k)
3
−(4k)
3
+(k)
3
=8
k
3
=1
k=1
⇒x=3,y=4,z=1
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