# How do you solve #x=y+4# and #5x+3y=-20# using substitution?

##### 1 Answer

Mar 20, 2016

#### Explanation:

First we substitute in our value for

Then you expand the bracket and simplify it to find

Now we use our value for

We can then check our answer by substituting both values into the *other* equation:

So we know it's right!

It's really important to check your answers, as in a test, it could save you a whole load of marks despite only taking a few seconds:)

Hope this helps; let me know if I can do anything else:)