Well, u can tread the "sqrt(2)" as a variable, like "x"
so 4*sqrt(2) +7*sqrt(2) -3*sqrt(2) = sqrt(2)*(4 + 7 - 3) [you take sqrt(2) as a common coefficient, or variable, or factor w/e u wanna call it]
= sqrt(2)*(8)
=8*sqrt(2)
Normally, for class purposes, we stop there, and are not required to bother further, but if u use a calculator, then it gives 11.3137....
If u already knew this, then I'm sorry for wasting time lol
