Question

Solve the system of equations y=5x-1 y=9x-9

Answer 1

Answer:

Look at the equations:

y

=

−

9

x

−

21

and

y

=

5

x

+

7

Because both equations equal (y), they both equal the same.

If an equations says "

y

=

−

9

x

−

21

" , that means we can replace (y) with

−

9

x

−

21

.

Therefore when i take the equation:

y

=

5

x

+

7

, we can replace (y) to get:

−

9

x

−

21

=

5

x

+

7

Now isolate (x):

−

9

x

−

21

=

5

x

+

7

⇔

−

21

=

14

x

+

7

⇔

−

28

=

14

x

⇔

x

=

−

2