This week we learned** verifying a solution**.

1 solution: m1 Is not equal to m2. no solution: m1=m2, b1=b2. coincident solution: m1=m2, b1=b2.

And then we learned substitution.

An algebraic method of finding solution for systems.

For example, **x**+4y=-3 **->x=-4y-3**

3**x** -y=29.

First, we nned to find the x or y who is It’s **independent**. It’s easy to calculate.

3(-4y-3)-7y=29.

-12y-9-7y=29.

-12y-7y=29+9=38.

-19y=38, y=-2.

We know y=-2, We can substitute y into the original formula. So the answer is (5, -2).

**Steps**: 1 **pick one equation** and rearrarrge so it is x or y.

2 substitute this into the other equation. (**use brackets**)

3 solve equation.

4 **substitute** the number just found, back into the rearranged equation.

5 verify solution.