lập được các số là: 2506, 2560, 2056, 2065, 2506, 2560, 5062, 5026, 5206, 5260, 5620, 5602, 6025, 6052, 6520, 6502, 6250, 6205

y:7x34=8704

y:7=8704:34

y:7=256

y=256x7

y=1792

Vậy y=1792

C nha

A=0,(36)-0,(71)

A=\(\dfrac{4}{11}\)-\(\dfrac{71}{99}\)

A=\(\dfrac{-35}{99}\)

B=[3,(12)-2,(5)]:0,(14)

B=[\(\dfrac{103}{33}\)-\(\dfrac{23}{9}\)]:\(\dfrac{14}{99}\)

B=\(\dfrac{-50}{33}\):\(\dfrac{14}{99}\)

B=\(\dfrac{-75}{7}\)

9656:(100+36)x12-345

=9656:136x12-345

=71x12-345

=852-345

=507

a)\(\dfrac{27^4.4^3}{9^5.8^2}\)

=\(\dfrac{3^{12}.2^6}{3^{10}.2^6}\)

=3\(^2\)=9

b)\(\dfrac{3^{29}.4^{16}}{27^9.8^{11}}\)

=\(\dfrac{3^{29}.2^{32}}{3^{27}.2^{33}}\)

=\(\dfrac{9}{2}\)

2:(\(\dfrac{1}{2}\)-\(\dfrac{2}{3}\))\(^2\)+0,125\(^3\)x8\(^3\)-(-12)\(^4\):36\(^2\)

=2:(\(\dfrac{-1}{6}\))\(^2\)+\(\dfrac{1}{512}\)x512+12\(^4\):1296

=2:\(\dfrac{1}{36}\)+\(\dfrac{1}{512}\)x512+20736:1296

=72+1+16

=73+16

=89

A=(...6)+(...4)+(.....6)+(....4)+(....6)

A=(....6)

vậy chữ số tận cùng của A bằng 6