Finding Magnitude of F - Vector E & Vector F Homework

[Allura]

Homework Statement

Let vector E = (10 i + 1 j) and vector F = (5 i - 5 j). Find the magnitude of F

Homework Equations

I thought it would just be 5^2 - 5^2 which equals 25-25, all square rooted.

The Attempt at a Solution

I keep getting 0 but it's not right. Help?

 

[Allura]

Nevermind, got it!