Question

Add. 3x + 5y – z, –2x –y –z, 7x + 3y –z​

Answer 1

Answer:

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Step-by-step explanation:

8x+y-3z

Answer 2

2x + 3y + z = 9 ------(1)

5x - 5y - z = -29 ----(2)

3x + y + 3z = 9 -----(3)

Add equations (1) and (2) and eliminate z

7x-2y =-20 -----(4)

Multiply equation (2) by 3 and add it to equation (3); Eliminate z again.

15x-15y-3z = -87

3x+y+3z = 9

add:

18x-14y = -78 ----(5)

7x-2y =-20 -----(4)

18x-14y = -78 ----(5)

We may solve for x and y from (4) and (5)

Multiply equation (4) by -7

-49x+14y =140

18x-14y =-78

Add:

-31x = 62

x=-2 ---- x solved

plug this x into equation (4) and solve for y

7(-2)-2y=-20

-14 -2y = -20

-2y = -6

y=3 --- y solved

Plug x=-2 , y=3 into equation (1)

2(-2)+3(3)+z = 9

-4+9+z=9

z=4 --- z solved

x=-2

y=3

z=4

(now replace the numbers and add or subtract)

HOPE THIS HELPED YOU! (^^)