Solving Systems (part 1)

It is simply two or more equations.

On the graph is ...

y = 2x + 1

y = -x + 7

To solve a system, you find the point where the lines intersect.

On this graph it is (2,5)

Plug in to each equation.

y = 2x + 1

5 = 2(2) + 1

5 = 4 + 1

5 = 5

y = -x + 7

5 = -2 + 7

5 = 5

​There is more than one way to solve systems.

The one I just showed was graphically.

We are not going to focus on that method.

I used it as an example so you would understand what the answer was

(as in where the lines cross)

​

We are going to focus on the method of SUBSTITUTION

​

​So let's look at a couple of different situations where we can use substitution.

y = 4x - 1

​y = 2x - 5

y = 3x + 8

​5x + 2y = 5

3x + 5y = 13

​2x + y = 4