13.(7x—49)—169=13⁵:13⁴

13.(7x—49)—169=13

13.(7x—49)=13+169

13.(7x—49)=182

7x—49=182:13

7x—49=14

7x=14+49

7x=63

x=63:7

x=9

13 . (7x - 49) - 169 = 13⁵  : 13⁴

13 . (7x - 49) - 169 = 13

       (7x - 49) - 169 = 13:13

       (7x - 49) - 169 = 1  

        7x - 49           = 1 + 169

        7x - 49           = 170

        7x                  = 170 - 49

        7x                  = 121

          x                  = 121 : 7     

          x                  = ?

\(13.\left(7x-49\right)-169=13^5:13^4\)

\(\Leftrightarrow13.\left(7x-49\right)-169=13^{5-4}\)

\(\Leftrightarrow13.\left(7x-49\right)-169=13\)

\(\Leftrightarrow13.\left(7x-49\right)=13+169\)

\(\Leftrightarrow13.\left(7x-49\right)=182\)

\(\Leftrightarrow7x-49=13:182\)

\(\Leftrightarrow7x-49=\frac{1}{14}\)

\(\Leftrightarrow7x=\frac{1}{14}+49\)

\(\Leftrightarrow7x=\frac{687}{14}\)

\(\Leftrightarrow x=\frac{687}{14}:7\)

\(\Leftrightarrow x=\frac{687}{98}\)

Học tốt #

  (36 x 15 x 169):(5 x 18 x 13)

= (18 x 2 x 3 x 5 x 13 x 13):(5 x 18 x 13)

= 2x3x13x(5 x 18 x 13):(5 x 18 x 13)

= 2 x 3 x 13

= 78

(169-4²).(169-5²)…(169-12²).(169-13²)

=(169-4²).(169-5²)…(169-12²).(169-169)

=(169-4²).(169-5²)…(169-12²).0

=0

(169 - 4^2) . (169 - 5^2) ... (169 - 13^2)

=(169-4^2).(169-5^2)...(169-169)

=0

0 nha   lamnuuyennhi

(169 - 4 mũ 2) (169 -5 mũ 2) ...( 169 - 13 mũ 2)

= (169-4²)(169-5²)...(169-13²)

=(199-4²)(169-5²)...(169-169)

=_____________...0

=       0

A) \(\frac{7^{2003}+7^{2002}}{7^{2004}}=\frac{7^{2003}}{7^{2004}}+\frac{7^{2002}}{7^{2004}}=\frac{1}{7}+\frac{1}{7^2}=\frac{8}{49}\)

B) Xem lại đề bài