# How do you evaluate #a-2y# when #a=-2/3# and #y=4/5#?

##### 1 Answer

Mar 5, 2018

You will get the answer

#### Explanation:

Evaluating something is basically substituting a value in for a variable. They give you value -2/3 for a, and they give you 4/5 for y. So when we sub those in we get the equation

So this looks pretty easy to solve. From here, if we use PEMDAS we see that we must multiply to by the fraction first and we get

Since we can't subtract without like denominators we want to find the lowest common denominator, which in this case will be 15. Now we have our new fractions

So if we subtract the two numerators we get -34

And this fraction can't be simplified so it is our final answer. Hope this helps!