Question

Rebecca solved

√45 + 2 √20. Her answer was 5 √5 . Is she correct? If not, explain and correct the error.

Answer 1

No.

`√(45)=3√(5) \\2√(20) =2\sqrt5}`

If you add them up you DO NOT GET
`5√(5).` According to mathematics, it equals to
`7√(5)`.