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39 votes
39 votes
Show your work and find the solution to the following system using substitution or elimination:

y = 2x - 1
y = 5x - 7

User Icco
by
2.9k points

1 Answer

12 votes
12 votes
Look at this from comments then you will find your answer, you’ll see why.
y
=
2
x
;

1
y
=
5
x

7

Rewrite equations:
y
=
2
x
;

y
=
5
x

7

Step: Solve
y
=
2
x
for y:
y
=
2
x

Step: Substitute
2
x
for
y
in

y
=
5
x

7
:

y
=
5
x

7

2
x
=
5
x

7

2
x
+

5
x
=
5
x

7
+

5
x
(Add -5x to both sides)

7
x
=

7

7
x

7
=

7

7
(Divide both sides by -7)
x
=
1

Step: Substitute
1
for
x
in
y
=
2
x
:
y
=
2
x
y
=
(
2
)
(
1
)
y
=
2
(Simplify both sides of the equation)

Answer:
x
=
1
and
y
User Seventh
by
2.7k points