Question

CAN SOMEONE HELP ME WITH THIS PLEASE IT DUE IN 15 MINS
solving systems of three equations with elimination
-x-5y+4z=19
4x-5y+4z=19
x+5y=-z=-20

Answer 1

Answer:

x-5y+4z=19___(1)

4x-5y+4z=19__(2)

x+5y=-z=-20__(3)

from 1&3

x-5y+4(-x-5y)=19

x-5y-4x-20y=19

-3x-25y=19____(4)

multiply (3) by 5

so, 5x+25y=-100___(5)

now add (4)&(5)

2x=81; x=81/2 put into (3)

x+5y=-20

(81/2)+5y=-20

5y=-20-(81/2)

5y=(-40-81)/2

5y= -121/2

y= -121/10