có k nhá

45 + 26 +84 + 92 + 475

= ( 45 + 475 ) + ( 26 +84 ) + 92

= 520 + 110 + 92

= 722

=(45+475)+(26+84)+92

=520+110+92

722

=[-26+(-15)]+16+26

=(-41)+16+26

=(-25)+26

=1.

   -26 +  ( -15 ) + l -16l + 26

= -26 + ( -15 ) + 16 + 26

= -26 + 26 + ( -15 ) + 16

= 0 + ( -15 ) + 16

= 1

\(-26+\left(-15\right)+|-16| +26\)

\(=-26+\left(-15\right)+16+26\)

\(=-26+26+\left(-15\right)+16\)

\(=0+\left(-15\right)+16\)

\(=1\)

Đặt \(x=\sqrt[3]{26+15\sqrt{3}}+\sqrt[3]{26-15\sqrt[]{3}}\)

\(\Rightarrow x^3=52+3\sqrt[3]{\left(26+15\sqrt[]{3}\right)\left(26-15\sqrt[]{3}\right)}.x\)

\(\Leftrightarrow x^3=52+3x\)

\(\Leftrightarrow x^3-3x-52=0\)

\(\Leftrightarrow\left(x-4\right)\left(x^2+4x+13\right)=0\)

\(\Leftrightarrow\left(x-4\right)\left[\left(x+2\right)^2+9\right]=0\)

\(\Leftrightarrow x=4\)

\(\frac{x}{13}+\frac{15}{26}=\frac{23}{26}\)

\(\Leftrightarrow\frac{x}{13}=\frac{8}{26}\)

\(\Leftrightarrow\frac{x}{13}=\frac{4}{13}\)

\(\Leftrightarrow x=4\)

\(\frac{x}{13}+\frac{15}{26}=\frac{23}{26}\)

\(\Leftrightarrow\frac{x}{13}=\frac{23}{26}-\frac{15}{26}\)

\(\Leftrightarrow\frac{x}{13}=\frac{8}{26}\)

\(\Leftrightarrow\frac{2x}{26}=\frac{8}{26}\)

\(\Leftrightarrow2x=8\)

\(\Leftrightarrow x=8:2\)

\(\Leftrightarrow x=4\)

Ko ghi lại đề bài:

\(=>\frac{x}{13}=\frac{8}{26}\)

\(=>\frac{x}{13}=\frac{4}{13}\)

\(=>x=4\)

=-3/26(-15/29-2/19)

=-3/26*(-17/19)

=3/26*17/19

=51/494

\(-\dfrac{3}{26}.\left(-\dfrac{15}{19}\right)-\dfrac{2}{19}.\left(-\dfrac{3}{26}\right)\)

\(=-\dfrac{3}{26}.\text{[}\left(-\dfrac{15}{19}-\dfrac{2}{19}\right)\)

\(=-\dfrac{3}{26}.\left(-\dfrac{17}{19}\right)\)

=\(\dfrac{51}{494}\)

=-3/26(-15/29-2/19)

=-3/26*(-17/19)

=3/26*17/19

=51/494

Cm nó bằng 4 ạk!!!! Thưa các bác!

\(\frac{\left(39+13\right)x2}{\left(84+57\right)x2}=\frac{78+26}{168+104}\)

\(\sqrt[3]{26+15\sqrt{3}}+\sqrt[3]{26-15\sqrt{3}}\)

=\(\sqrt[3]{\left(\sqrt{3}+2\right)^3}+\sqrt[3]{\left(\sqrt{3}-2\right)^3}\)

=\(\sqrt{3}+2+\sqrt{3}-2=2\sqrt{3}\)