Question

Why are these incorrect 3sqrt 7 - sqrt 7 =3

Answer 1

`\bf 3√(7)-√(7)=3\implies 3√(7)-1√(7)=3\implies \stackrel{\textit{adding like-terms}}{2√(7)\\e 3}`

bear in mind that 3√7, is really 1√7 + 1√7 + 1√7, if we subtract 1√7 from it, we're left with 2√7.

Answer 2

Because the left side sqrt is multiplied by 3 if it was just added it would be correct because it would cancel out and leave the 3’s. Since it’s multiplied it would change the value