126 - 126 . (x - 6) = 99

126 . [ 1 - ( x - 6)] = 99

126 . [ 1 - x + 6 ] = 99

126 . [ 7 - x ] = 99

7 - x = 11/14

x = 7 - 11/14 = 87/14

126 - 126 . (x - 6) = 99

126 . (x - 6)=27

x - 6 =3/14

x=3/14 + 6

x=87/14

126 - 126 . (x - 6) = 99

126 . [ 1 - ( x - 6)] = 99

126 . [ 1 - x + 6 ] = 99

126 . [ 7 - x ] = 99

7 - x = 11/14

x = 7 - 11/14 = 87/14

\(\dfrac{90}{126}=\dfrac{5}{7}\)

\(\Rightarrow\dfrac{90}{126}< \dfrac{6}{7}\) (Vì \(\dfrac{5}{7}< \dfrac{6}{7}\))

\(\dfrac{35}{49}=\dfrac{5}{7}\)

\(\Rightarrow\dfrac{90}{126}=\dfrac{35}{49}\) (Vì \(\dfrac{5}{7}=\dfrac{5}{7}\))

\(\dfrac{90}{126}\) = \(\dfrac{90:18}{126:18}\) = \(\dfrac{5}{7}\) so sánh \(\dfrac{5}{7}< \dfrac{6}{7}\) nên \(\dfrac{90}{126}< \dfrac{6}{7}\)

\(\dfrac{90}{126}=\dfrac{5}{7}\) và \(\dfrac{35}{49}\) = \(\dfrac{35:7}{49:7}=\dfrac{5}{7}\) so sánh \(\dfrac{5}{7}=\dfrac{5}{7}\) nên \(\dfrac{90}{126}=\dfrac{35}{49}\)

\(\dfrac{4^9\cdot36+64^4}{100\cdot16^4}=\dfrac{2^{20}\cdot3^2+2^{24}}{2^{18}\cdot5^2}=\dfrac{2^{20}\left(3^2+2^4\right)}{2^{18}\cdot5^2}=4\)

 ko bt

a)\(\left(-4\right).125.\left(-25\right).\left(-6\right).\left(-8\right)\)

\(=\left[\left(-4\right)\cdot\left(-25\right)\right]\cdot\left[125\cdot\left(-8\right)\right]\cdot\left(-6\right)\)

\(=100\cdot\left(-1000\right)\cdot\left(-6\right)\)

\(=600000\)

b) \(\left(-98\right)\cdot\left(1-126\right)-126\cdot98\)

\(=\left(-98\right)\cdot1-\left(-98\right)\cdot126-126\cdot98\)

\(=\left(-98\right)+98\cdot126-126\cdot98\)

\(=\left(-98\right)\)

0,875

0,875

0.875

11 đmm

l-45l.l3l+l-126l:l-6l

=45.3+126:6

=135+21=156

=45.3+126:6

=135+21

=156

\(=63-\dfrac{11}{6}-\dfrac{13}{11}=\dfrac{3959}{66}\)