# How do you solve #x + 4y = 8# and #2x + y = 9# using matrices?

##### 1 Answer

#### Answer:

#### Explanation:

In preamble, we can write these equations in column vector form, ie:

And so they can also be written in matrix form, as we then have a set of rules in **matrix algebra** which means they are the same thing:

That is:

From here, we have choices. We can row reduce, but as we are looking at the simplest matrix algebra (I think), we should try to use the inverse matrix

Generally speaking, for a

So we have: