SOLUTION: Obtain an equivalent system by performing the stated elementary operation on the system. Replace the first equation by the sum of itself and 3 times the third equation. 9x + 9y

Algebra ->  Finance -> SOLUTION: Obtain an equivalent system by performing the stated elementary operation on the system. Replace the first equation by the sum of itself and 3 times the third equation. 9x + 9y       Log On


   

Question 1077265: Obtain an equivalent system by performing the stated elementary operation on the system. Replace the first equation by the sum of itself and 3 times the third equation.
9x + 9y + 14z = -18
5x - 8y + 8z = 20
4x - 8y - 3z = 8
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
First equation becomes, 9x%2B9y%2B14z%2B3%2A4x-3%2A8y-3%2A3z=-18%2B3%2A8

9x%2B12x%2B9y-24y%2B14z-9z=24-18

highlight_green%2821x-15y%2B5z=6%29----just the first equation, its equivalent.