Question

Решите: а) √5+√20+√45; б) 3√3-5√27+2√48.

Answer 1

√ 5 + √ 20 + √ 45 = √ 5 + 2 √ 5 + 3 √ 5 = 6 √ 5 
3 √ 3 - 5 √ 27 + 2 √ 48 = 3 √ 3 - 15 √ 3 + 8 √ 3 = - 4 √ 3 

Answer 2

$sqrt{5} + sqrt{20} + sqrt{45}= sqrt{5} + sqrt{5*4} + sqrt{5*9}= sqrt{5}+2 sqrt{5}+3 sqrt{5}=6 sqrt{5}$
$3 sqrt{3}-5 sqrt{27}+2 sqrt{48}=3 sqrt{3}-5 sqrt{3*9}+2 sqrt{3*16}=3 sqrt{3}-5*3 sqrt{3}+2*4 sqrt{3}=3 sqrt{3}-15 sqrt{3}+8 sqrt{3}=-4 sqrt{3}$