Question

simplify 4√5-3√20+√45​

Answer 1

Answer:

√45 −3 √20+4√5

= √3×3×5 −3 √2×2×5 +4 √5

=3 √5 −−6 √5 +4 √5

=7 √5−6 √5

= √5

Answer 2

$4 \sqrt{5} - 3 \times 2 \sqrt{5} + 3 \sqrt{5} \\ \\ 4 \sqrt{5} - 6 \sqrt{5} + 3 \sqrt{5} \\ \\ { \boxed{ \sqrt{5}}}$