HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Thanks For helping me in advance!

2x-y-3z=7.           (1)

3x+y+z=10.         (2)

5x+y+2z=15.       (3)

 

Add equations (1) and (2) term by term:   5x - 2z = 17.       (4)

Add equations (1)and (3) term by term:    7x - z = 22.         (5)

 

From (5) we have:   z = 7x - 22.     (6)

 

Put this in (4):  5x - 2(7x-22) = 17

                        5x - 14x + 44 = 17

                        -9x = -27

                           x = 3.              (7)

 

Put (7) into (6):   z = -1.             (8)

 

Put (7) and (8) into (1):   6 - y + 3 = 7

                                       y = 2

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Hi Qaz,

I would do these with matrices but is there are still different methods.

Which method have ou been taught. If i know it I will try to do it the way you have been taught ://