For this case we have the following system of equations:

Equating the values of y we have:

From here, we can clear the value of x.
We have then:

Then, we look for the value of y.
For this, we substitute x in any of the equations:
Answer:
The ordered pair solution of the system of equations, is given by:
Step-by-step explanation:
we know that
Work =f*d
=25*100
=2500Joule
therefore work done is 2500Joule
I:2x – y + z = 7
II:x + 2y – 5z = -1
III:x – y = 6
you can first use III and substitute x or y to eliminate it in I and II (in this case x):
III: x=6+y
-> substitute x in I and II:
I': 2*(6+y)-y+z=7
12+2y-y+z=7
y+z=-5
II':(6+y)+2y-5z=-1
3y+6-5z=-1
3y-5z=-7
then you can subtract II' from 3*I' to eliminate y:
3*I'=3y+3z=-15
3*I'-II':
3y+3z-(3y-5z)=-15-(-7)
8z=-8
z=-1
insert z in II' to calculate y:
3y-5z=-7
3y+5=-7
3y=-12
y=-4
insert y into III to calculate x:
x-(-4)=6
x+4=6
x=2
so the solution is
x=2
y=-4
z=-1
Answer:
The lengths of all sides of the patio are 15, 15, 9, 9.
Pls thank if this helped!! :)