Question

X/radical din 21-radical din 42/5=2 radical din 42/15

Answer 1

x / √21 - ( √42 / 5 ) = 2√42 / 15

√21 X / 21 = 2√42 / 15 + √42 / 5 = 2√42/ 15 + 3√42 / 15 = 5√42/15 = √42/3

3√21 X = 21√42 l : 3

√21 X = 7√21 · √2 l : √21

X = 7√2

Answer 2

x/√21=√42/5+2√42/15

amplificam cu√21

x=21*√2/5+2*21√2/15

x=21√2*(3+2)/15

x=21√2/3

x=7√2

obs

am tinut cont de ordinea operatiilor, asa cum ai scris tu textul;se efectueaza intai radicalii, apoi impartirile

dac vroiai radical din (42/5) sau (42/15) ar fi trebuitr sa scrii√(42/5) , respectiv,√(42/15)