117, 279

Vì 1+1+7+1+9+2+2+7+9+8+1+2=50

ta có công thức tổng các chữ số của một số mà chia hết cho 9 thì số đó chia hết cho 9

=>117 192 279 812 ko chia hết cho 9

nhóm 7 phần 9 ra ngoài rồi tính

Bằng \(-\frac{5}{6}\)

a,    6/7+5/9+8/7-2/9=(6/7+8/7)+(5/9-2/9)=14/7+3/9=2+1/3=7/3

b, 5+7/3=22/3

a/ \(\frac{6}{7}+\frac{5}{9}+\frac{8}{7}-\frac{2}{9}\)

= \(\left(\frac{6}{7}+\frac{8}{7}\right)+\left(\frac{5}{9}-\frac{2}{9}\right)\)

=  \(2+\frac{1}{3}\)

= \(\frac{7}{3}\)

b/ 5+\(2\frac{1}{3}\)

= 5 + \(\frac{7}{3}\)

= \(\frac{22}{3}\)

a) 5⁴ : 5² + 3² . 3³

= 5² + 3⁵ = 25 + 243 = 268

Học tốt!!!

a) 5⁴:5²+3².3³=5² + 3⁵=25+243 = 278

b) 3+6+9+12+...+96

=3.1+3.2+3.3+3.4+...+3.32

=3.(1+2+3+4+...+32)

=3.\(\frac{\left(32+1\right).32}{2}\)=\(3.33.16=1584\)

-3/18-12/9

=-1/6+-4/3

=-1/6+-8/6

=-9/6

=-3/2

-49/115:7/-115

=-49/115x-115/7

=7

a)   -3/18 -12/9

=  -1/6 - 4/3

=  -1/6 - 8/6

= -1-8/6

= -9/6

= -3/2

= -1/1/2 

a.\(12^7:6^7=\left(12:6\right)^7=2^7\)

b. \(27^5:81^3=\left(3^3\right)^5:\left(3^4\right)^3=3^{15}:3^{12}=3^3\)

c. \(18^3:9^3=\left(18:9\right)^3=2^3\)

d. \(125^3:25^4=\left(25^3\right)^3:25^4=25^9:25^4=25^5\)

12^7:6^7=(12:6)^7=2^7

27^5:81^3=(3^3)^5:(3^4)^3=3^15:3^12=3^3

18^3:9^3=(18:9)^3=2^3

125^3:25^4=(5^3)^3:(5^2)^4=5^9:5^8=5

\(\frac{5}{9}-\frac{7}{13}-\frac{5}{9}.\frac{3}{13}+\frac{-5}{9}.\frac{6}{9}\)

= \(\frac{5}{9}-\frac{7}{13}-\frac{5}{3}.\frac{1}{13}+\frac{-5}{3}.\frac{2}{9}\)

=\(\frac{5}{9}-\frac{7}{13}-\frac{5}{39}+\frac{-10}{27}\)

=\(\frac{5}{9}+\frac{-7}{13}+\frac{-5}{39}+\frac{-10}{27}\)

=\(\frac{-13}{27}\)

Chúc bạn học tốt nhea ♥♥♥

\(\frac{5}{9}-\frac{7}{13}-\frac{5}{9}.\frac{3}{13}+\frac{-5}{9}.\frac{61}{9}\)

\(=\frac{5}{9}\left(1-\frac{3}{13}\right)-\frac{7}{13}-\frac{5}{9}.\frac{61}{9}\)

\(=\frac{5}{9}.\frac{10}{13}-\frac{5}{9}.\frac{61}{9}-\frac{7}{13}\)

\(=\frac{5}{9}\left(\frac{10}{13}-\frac{61}{9}\right)-\frac{7}{13}\)\(=-\frac{314}{81}\)

\(M=\frac{1}{16}=0,0625\)

Dễ

Đúng 100%

Đúng 100%

Đúng 100%