8/195

Ta có: \(\dfrac{4}{15}\) + \(\dfrac{2}{13}\) = \(\dfrac{52+30}{195}\) = \(\dfrac{82}{195}\)

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17+18 = 171 nhé

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17+18.  = 171

\(1\frac{2}{5}+75\%-0,4\div\frac{5}{3}-\left(\frac{-13}{15}\right).\)

= \(\frac{7}{5}+\frac{3}{4}-\frac{2}{5}\div\frac{5}{3}-\left(\frac{-13}{15}\right)\)

= \(\frac{43}{20}-\frac{6}{25}-\left(\frac{-13}{15}\right)\)

= \(\frac{833}{300}\)

bn làm cách ngan gọn hộ mk đc ko, số to quá, mk ko làm đc

nha bn

\(a,12-\left(4+105-13\right)+\left(4+105-3\right)\)

\(=12-4-105+13+4+105-3\)

\(=12+\left(-4+4\right)+\left(-105+105\right)+\left(13-3\right)\)

\(=12+0+0+10\)

\(=22\)

\(b,-15+\left(-17+21-35\right)+\left(4+105-13\right)\)

\(=-15-17+21-35+4+105-13\)

\(=\left(-15-35\right)+\left(-17-13\right)+\left(21+4+105\right)\)

\(=-50-30+130\)

\(=-50+100\)

\(=50\)

\(c,\left(\left|-5\right|+\left|+7\right|+\left|-9\right|\right)-\left(\left|+5\right|+\left|-7\right|+9\right)\)

\(=\left(5+7+9\right)-\left(5+7+9\right)\)

\(=0\)

a, -359+181+(-123)+350+(-172)

=((-359)+350)+((-172)+181)+(-123)

=(-9)+(9)+(-123)

=-123

b,-69+53+46+(-94)+(-14)+78

=((-69)+(-94)+(-14))+53+46+78

=(-177)+177

=0

c,13-12+11+10-9+8-7-6+5-4+3+2-1

=(13-12-1)+(11-7-4)+(10+3+2+8+5)+(-9+(-6))

=0+0+28+(-15)

=28-15

=13.

A=5 296 163 666_x10¹⁵