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

1 Answer
Mar 5, 2018

You will get the answer #-34/15#

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

#-2/3 - 2(4/5)#

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

#-2/3-8/5#

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

#-10/15-24/15#

So if we subtract the two numerators we get -34

#-34/15#

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