This week in math I have learned how to solve and sub with linear equations.

ex: y=3x-7 and y=-x+9

first, I would sub in -x+9 for y of y=3x-7

-x+9=3x-7

next I would subtract 9 from each side

-x+9=3x-7

-9 -9

then I would subtract 3x from each side

-x=3x-16

-3x -3x

Then I would divide each side by -4

-4x/-4=-16/-4

Which would make x=4. Now I would imput 4 into y=-x+9

Now to solve for y

y=-x+9

y=-(4)+9

y=5.

to double check my answer I would do the same with the other question:

y=3x-7

y=3(4)-7

y=12-7

y=5

That is how you do it.