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454

54

654

646

546

465

65

\(D=49+64+81+...+169\)

\(\Rightarrow D=\frac{\left(169+49\right)\left[\left(169-49\right):15+1\right]}{2}\)

\(\Rightarrow D=\frac{218.9}{2}\)

\(\Rightarrow D=981\)

Ko đúng đáp án phải là 728

49+64+81+..............+169=7²+8²+9²+10²+11²+12²+13²=728

49+64+81+...+169

=>\(7^2+8^2+9^2+...+13^2\)

=>\(\left(7+8+9+10+11+12+13\right)^2\)

=>\(70^2\)

=>\(4900\)

CHÚC BẠN HOK TỐT !!!NGUYỄN THƯ LÀM SAI RỒI NHÉ

= 728

       hok tốt^^

D = 49+ 64+81+...+169

   =7²+8²+9²+....+13²

    =728

tớ gợi ý cho :

49 = 7 . 7

64 = 8.8

81 = 9.9

169 =13.13

\(\Rightarrow D=7^2+8^2+9^2+10^2+11^2+12^2+13^2\)

     \(D=728\)

Vậy D = 728

\(2+4+6+8+...+150=\frac{\left(150+2\right)\left[\left(150-2\right)\div2+1\right]}{2}\)

\(=\frac{152.75}{2}=76.75=5700\)

\(7+10+13+...+76=\frac{\left(76+7\right)\left[\left(76-7\right)\div3+1\right]}{2}\)

\(=\frac{83.24}{2}=83.12=996\)

\(49+64+81+...+169=7^2+8^2+9^2+...+13^2=584\)

=2/10+3/10+4/10+......+13/10

=\(\frac{2+3+4+......+13}{10}\)

=90/10=9

k cho mình nha

=9 nhe cac ban

D=49+64+81+..+169

=>D=7²+8²+9²+10²+11²+12²+13²

=>D=728

Nhớ tick cho tui nhé chúc bn học tốt !!! và ko có công thức j nhé @@

A)7^2

13^2

10^2

14^2

9^2

B)10^3

6^3

8^3

1^3

4^3

a) 49= 7⁷, 100= 10², 81=9² , 169=13^{2 ,} 196 = 14²

b) 1000 = 10³ , 216 = 6³ , 343 = 7³ , 512 = 8³, 1= 1³ , 64 = 4³

49 = 7² ; 169 = 13² ; 100 = 10² ; 196 = 14² ; 81 = 9²

1000 = 10³ ; 216 = 6³;343 = 7³ ; 512 = 8³ ; 1 = 1³ ; 64 =  4³