Question

5,4:0,4*1420+4,5*780*3/3+6+9+12+15+18+21+24+27

Answer 1

Đặt 

5,4:0,4 × 1420 + 4,5 × 780 × 3

= 13,5 × 1420 + 13,5 × 780
= 13,5 × 1420 + 780
= 13,5 × 2200
= 29700

3 + 6 + 9 + 12 + 15 + 18 + 21 + 24 + 27

= 3 + 27 + 6 + 24 + 9 + 21 + 12 + 18 + 15
= 30 + 30 + 30 + 30 + 15
= 30 × 4 + 15
= 120 + 15
= 135

\(\Rightarrow\)\(\frac{29700}{135}\)

Answer 2

\(\frac{\text{5,4:0,4x1420+4,5x780x3}}{3+6+9+12+15+18+21+24+27}\)=220