\(419:\left(8\times8\times4,18+0,17\times2,5+2,09\times2\times36+0,23\times2,5\right)\)

\(=419:\left(64\times4,18+0,17\times2,5+4,18\times36+0,23\times2,5\right)\)

\(=419:\left[\left(64+36\right)\times4,18+\left(0,17+0,23\right)\times2,5\right]\)

\(=419:\left[100\times4,18+0,4\times2,5\right]\)

\(=419:\left[418+1\right]\)

\(=419:419\)

\(=1\)

\(=\dfrac{419}{64\cdot4.18+0,17\cdot2,5+2,09\cdot72+0,23\cdot2,5}\)

\(=\dfrac{419}{0,4\cdot2,5+64\cdot4,18+2,09\cdot72}\)

\(=\dfrac{419}{1+418}=1\)

a: 81:0,125-81:0,2-81:0,5

=81x8-81x5-81x2

=81x(8-5-2)

=81x1=81

\(\text{34,75 x 120 - 34,75 x 19 - 34,75}\)

\(=34,75.\left(120-19-1\right)\)

\(=34,75.100\)

\(=3475\)

học tốt

\(34,75\times120-34,75\times19-34,75\)

\(=34,75\times120-34,75\times19-34,75\times1\)

\(=34,75\times\left(120-19-1\right)\)

\(=34,75\times100\)

\(=3475\)

=240:8+25x4+7x10

=30+100+70

=200

Tính thuận tiện :
19,76 x 98,68 - 19,76 x 36,49 + 19,76 x 37,81
= ( 98,68 - 36,49 + 37,81 ) x 19,76
= 100 x 19,76
= 1976.
.>>>>>

Tính thuận tiện :

19,76 x 98,68 - 19,76 x 36,49 + 19,76 x 37,81

= ( 98,68 - 36,49 + 37,81 ) x 19,76

=          100 x 19,76

=              1976.

nếu đc thì t*** mk nhé!!!!

\(\left(1+\frac{1}{2}\right)\times\left(1+\frac{1}{3}\right)\times\left(1+\frac{1}{4}\right)\)

\(=\frac{3}{2}\times\frac{4}{3}\times\frac{5}{4}\)

\(=\frac{5}{2}\)

p/s: chúc bạn học tốt

   999 x 4,26 - 333 x 2,78

= 333 x 2 x 4,26 - 333 x 2,78

= 333 x ( 2 x 4,26 - 2,78 )

= 333 x 5,74

= 1911,42

   999x4,26-333x2,78

=333x3x4,26-333x2,78

=333x12,78-333x2,78

=333x(12,78-2,78)

=333x10

=3330

4,5 : 100 + 4,5 + 8,99 x 4,5

=45x0,01+4,5x1+8,99x4,5

=4,5x(0,01+1+8,99)

=4,5x10

=45

#YM

    8,12x6+16,24x4-4,06x8

=8,12x6+8,12x2x4-8,12x0,5x8

=8,12x[6+8-4]

=8,12x10

=81,2

ta có

8,12*6=8,12*2*3=16,24*3

4,06*8=4,06*8=4,06*4*2=16,24*2

thay vào đầu bài thì ta có

16,24*3+16,24*4-16,24*2

=16,24*7-16,24*2

=16,24*5

=81,2