\(23.18+18.\left(-23\right)\)

\(=23.18+\left(-18\right).23\)

\(=23.\left(-18+18\right)\)

\(=23.0=0\)

23.18 + 18.(-23)

= 23.18 - 23.18

= 0

trình bày chi tiết với ạ;-;

\(=23\cdot15-115+13=243\)

= 23 . 15 - ( 115 - 13 )

= 345 - 102 = 243

Ta có: \(2^3\cdot15-\left\lbrack115+\left(12-25\right)\right\rbrack\)

\(=8\cdot15-115-\left(12-25\right)\)

=120-115-(-13)

=5+13

=18

\(\frac{9.11+32.9}{23.15+12.23}=\frac{3^2.11+32.3^2}{23.3.5+12.23}\)

\(=\frac{3^2.\left(11+32\right)}{23.\left(15+12\right)}=\frac{3^2.43}{23.27}\)

\(=\frac{3^2.43}{23.3^3}=\frac{43}{23.3}=\frac{43}{69}\)

22,7611663

\(\left(23.18\right):\left(23.2\right)=\dfrac{23.18}{23.2}=\dfrac{18}{2}=9\)

 (23.18) : (23.2)= (23:23) . (18:2)= 1.9=9

\(9.11+32.9=99+288=387\)

a) \(9.11+32.9=9.\left(11+32\right)=9.43=387\)

b) \(23.25+12.23=23.\left(25+12\right)=23.37=851\)

c)  \(12.13+24.26+36.39=12.13+12.2.13.2+12.3.13.3\)

                                                          \(=12.13+2^2\left(12.13\right)+3^2\left(12.13\right)\)

                                                            \(=12.13.\left(1+2^2+3^2\right)=12.13.14=2184\)

d) Câu này tương tự câu trên nha.

b: \(17\cdot83+16\cdot83+17\cdot33\)

\(=83\left(17+16\right)+17\cdot33\)

\(=83\cdot33+17\cdot33=33\left(83+17\right)=33\cdot100=3300\)

b: \(240:15\cdot4=16\cdot4=64\)

d: \(\frac{23\cdot18}{23\cdot2}=\frac{18}{2}=9\)

[( 4x + 48 ) . 3 + 55 ] : 5 = 35

( 4x + 48 ) . 3 + 55 = 35 . 5 = 175

4x + 48 = 175 : 3 = 175/3

4x = 175/3 - 48 = 31/3

x = 31/3 : 4 = 31/12=2/7/12