2⁹ : 2⁷ = 2^9-7 = 2² = 4 hay 2⁹ : 2⁷ = 512 : 128 = 4

3⁷ : 3⁵ = 3^7-5 = 3² = 9 hay 3⁷ : 3⁵ = 2187 : 243 = 9

7⁴ : 7⁴ = 7^4-4 = 7⁰ = 1 hay 7⁴ : 7⁴ = 2401 : 2401 = 1

\(A=\left(b,u,t,s,a,c,h,v,ơ\right)\)

ban co the viet lai ko

A = { b;u;t;s;a;c;h;v;ơ }

k mk nha

\(200:9=22\left(dư2\right)\)

=\(\frac{5-3}{3\cdot5}\)+ \(\frac{7-5}{5\cdot7}\)+ \(\frac{9-7}{7\cdot9}\)+...+ \(\frac{39-37}{37\cdot39}\)

= \(\frac{5}{3\cdot5}\)- \(\frac{3}{3\cdot5}\)+ \(\frac{7}{5\cdot7}\)- \(\frac{5}{5\cdot7}\)+ \(\frac{9}{7\cdot9}\)- \(\frac{7}{7\cdot9}\)+...+ \(\frac{39}{37\cdot39}\)- \(\frac{37}{37\cdot39}\)

= \(\frac{1}{3}\)- \(\frac{1}{5}\)+ \(\frac{1}{5}\)- \(\frac{1}{7}\)+ \(\frac{1}{7}\)- \(\frac{1}{9}\)+...+ \(\frac{1}{37}\)- \(\frac{1}{39}\)

= \(\frac{1}{3}\)- \(\frac{1}{39}\)

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

5 /2+7 /2=12 /2