=(5×4×2)×(√ 13)? =2√2- 1√2+ 10√ 10
=40× 13 =(2- 1+ 10)×√2
=520 = 1 1√2
(- 1/2)×(-2/3)×(-3/4)×(-4/5) -3? ×(-3)?
= 1/3×(-3/4)×(-4/5) =-9×9
=- 1/4×(-4/5) =-8 1
= 1/5
Please ask questions if you don't understand, dear ~