What cards?
I don’t get it
Quick steps to solve this.
1. Lets square both. (X +Y)*2 = 7*7
2. Then, X*2 + 2XY + Y*2 = 49
3. Since XY is given to 4, X*2 + 8 + Y*2 = 49
4. Move 8
5. X*2 + Y*2 = 49 - 8
6. X*2 + Y*2 = 41
The answer is "41" Boom!
if i'm correct n= 1 if you need a explanation let me know