\(-15,5\times20,8+3,5\times9,2-15,5\times9,2+3,5\times20,8.\)

\(=20,8\times\left(3,5-15,5\right)+9,2\times\left(3,5-15,5\right)\)

\(=\left(3,5-15,5\right)\times\left(20,8+9,2\right)\)

\(=\left(-12\right)\times30\)

\(=-360\)

 -15,5 x 20,8 + 3,5 x 9,2- 15,5 x 9,2 + 3,5 x 20,8=-360

k mk nha mn 

=-360 nha pạn

46,05

141,75

\(x\div6,14=21,2-13,7\)

\(x\div6,14=7,5\)

\(x=7,5\times6,14\)

\(x=46,05\)

\(x\div3,5=50-9,5\)

\(x\div3,5=40,5\)

\(x=40,5\times3,5\)

\(x=141,75\)

x:6,14=21,2-13,7=7,5=>x=7,5*6,14=46,05

x:3,5=50-9,5=40,5  =>x=40,5*3,5=141,75

\(-15,5.20,8+3,5.9,2-15,5.9,2+3,5.20,8\)

\(=-15,5\left(20,8+9,2\right)+3,5\left(9,2+20,8\right)\)

\(=\left(-15,5\right).30+3,5.30\)

\(=30.\left(-12,5\right)\)

\(=-375\)

\(-15,5.20,8+3,5.9,2-15,5.9,2+3,5.20,8\)

\(=20,8.\left(-15,5+3,5\right)+9,2.\left(-15,5+3,5\right)\)

\(=\left(-15,5+3,5\right).\left(20,8+9,2\right)\)

\(=\left(-12\right).30\)

\(=-360\)

Vậy : \(-15,5.20,8+3,5.9,2-15,5.9,2+3,5.20,8=-360\)

\(-15,5.20,8+3,5.9,2-15,5.9,2+3,5.20,8\)

= \(20,8.\left(-15,5+3,5\right)+9,2.\left(-15,5+3,5\right)\)

= \(20,8.\left(-12\right)+9,2.\left(-12\right)\)

= \(\left(20,8+9,2\right).\left(-12\right)\)

= \(30.\left(-12\right)\)

= \(-360.\)

Chúc bạn học tốt!

= -15,5 .( 20,8 - 9,2) + 3,5 . (9,2+20,8)

=-15,5 . 11,6 + 3,5 .30

=-179,8+105

=-74,8

\(-15,5.20,8+3,5.9,2-15,5.9,2+3,5.20,8\)

\(=-15,5\left(20,8+9,2\right)+3,5\left(9,2+20,8\right)\)

\(=\left(9,2+20,8\right)\left(-15,5+3,5\right)\)

\(=30.\left(-12\right)=-360\)

cau a x=1