Which is the exact value of the expression sqrt 32- sqrt 50 + sqrt 128

Question

2 sqrt 7
7 sqrt 2
22 sqrt 2
2 sqrt 55

Answer 1

sqrt(32)=sqrt(2)*sqrt(16)=sqrt(2)*4

sqrt(50)=sqrt(2)*sqrt(25)=sqrt(2)*5

sqrt(128)=sqrt(2)*sqrt(64)=sqrt(2)*8

sqrt(32)-sqrt(50)+sqrt(128)=

sqrt(2)*4-sqrt(2)*5+sqrt(2)*8=

sqrt(2)*(4-5+8)=

sqrt(2)*7

OR

7*sqrt(2)