Question

Which choice is equivalent to the expression below?

2√2 + √18 + √8

A.7√2
B.8√2
C.6√2
D.4√2

Answer 1

`√(18) = √(3*3*2) = 3√(2) \\ √(8) = √(2*2*2) =2 √(2) \\ 2 √(2) + 3 √(2) + 2√(2) = 7 √(2)`

Answer 2

`2\sqrt2+√(18)+\sqrt8=2\sqrt2+√(9\cdot2)+√(4\cdot2)\\\\=2\sqrt2+\sqrt9\cdot\sqrt2+\sqrt4\cdot\sqrt2=2\sqrt2+3\sqrt2+2\sqrt2=7\sqrt2\\\\Answer:A.\ 7\sqrt2`