Answers

2014-03-11T21:04:36+05:30
Finding Determinant
D =   \left[\begin{array}{ccc}3&4&5\\2&-1&8\\5&-2&7\end{array}\right]
=3(-7+16)-4(14-40)+5(-4+5) = 136

Dx = \left[\begin{array}{ccc}18&4&5\\13&-1&8\\20&-2&7\end{array}\right]
=18(-7+16)-4(91-160)+5(-26+20) = 408

Dy = \left[\begin{array}{ccc}3&18&5\\2&13&8\\5&20&7\end{array}\right]
=3(91-160)-18(14-40)+5(40-65) = 136

Dz = \left[\begin{array}{ccc}3&4&18\\2&-1&13\\5&-2&20\end{array}\right]
=3(-20+26)-4(40-65)+18(-4+5) = 136

Therefore x = Dx/D  = 408/136 = 3
y = Dy/D = 136/136 = 1
z= Dz/D = 136/136 = 1
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