a

2⁴-4²=0

=>(2¹⁷ + 17²).(9¹⁵ - 3¹⁵).(2⁴ - 4²)=0

b

(7¹⁹⁹⁷ - 7¹⁹⁹⁵) : (7¹⁹⁹⁴.7)

=7¹⁹⁹⁵(7²-1):7¹⁹⁹⁵=48

c) (1² + 2³ + 3⁴ + 4⁵).(1³+ 2³ + 3³ + 4³).(3⁸ - 81²)

=(1² + 2³ + 3⁴ + 4⁵).(1³+ 2³ + 3³ + 4³).0=0

d) (2⁸ + 8³) : (2⁵.2³)

=(2⁸+2⁹);2⁸=3

A=0

B=0

C=0

D=3

4:

a: =4/15-2,9+11/15=1-2,9=-1,9

b: \(=-36,75+3,7-63,25+6,3=10-100=-90\)

c: \(=6,5+3,5-\dfrac{10}{17}-\dfrac{7}{17}=10-1=9\)

d: \(=\dfrac{13}{25}\left(-39,1-60,9\right)=\dfrac{13}{25}\left(-100\right)=-52\)

e: =-5/12-7/12-3,7-6,3=-1-10=-11

f: =2,8(-6/13-7/13)-7,2=-2,8-7,2=-10

cậu tách ra từng bài thôi nha.

Bài 1 :

a) \(\left(2^{17}+17^2\right).\left(9^{15}-3^{15}\right).\left(2^4-4^2\right)\)

\(=\left(2^{17}+17^2\right).\left(9^{15}-3^{15}\right).\left(16-16\right)\)

\(=\left(2^{17}+17^2\right).\left(9^{15}-3^{15}\right).0\)

\(=0\)

câu b sai đề rồi bạn , mình sủa lại đề nha :

b) \(\left(8^{2017}-8^{2015}\right)\div\left(8^{2014}.8\right)\)

\(=\left(8^{2017}-8^{2015}\right)\div8^{2015}\)

\(=8^{2017}\div8^{2015}-8^{2015}\div8^{2015}\)

\(=8^2-1\)

\(=64-1\)

\(=63\)

c) \(\left(1^3+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left(3^8-81^2\right)\)

\(=\left(1^3+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left[3^8.\left(3^4\right)^2\right]\)

\(=\left(1^3+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left[3^8-3^8\right]\)

\(=\left(1^3+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).0\)

\(=0\)

d) \(\left(2^8+8^3\right)\div\left(2^5.2^3\right)\)

\(=\left[2^8+\left(2^3\right)^3\right]\div2^8\)

\(=\left[2^8+2^9\right]\div2^8\)

\(=2^8\div2^8+2^9\div2^8\)

\(=1+2\)

\(=3\)

Bài 2 :

a) \(125^5\div25^3=\left(5^3\right)^5\div\left(5^2\right)^3=5^{15}\div5^6=5^9\)

b) \(27^6\div9^3=\left(3^3\right)^6\div\left(3^2\right)^3=3^{18}\div3^6=3^{12}\)

c) \(4^{20}\div2^{15}=\left(2^2\right)^{20}\div2^{15}=2^{40}\div2^{15}=2^{25}\)

d) \(24^n\div2^{2n}=24^n\div4^n=6^n\)

a) A = \(9\frac{3}{8}-\left(2\frac{3}{5}+2\frac{3}{8}\right)=9\frac{3}{8}-2\frac{3}{5}-2\frac{3}{8}=\left(9\frac{3}{8}-2\frac{3}{8}\right)-2\frac{3}{5}=7-\frac{13}{5}=\frac{22}{5}\)

b) B = \(\left(15\frac{3}{5}+5\frac{3}{4}\right)-8\frac{3}{5}=15\frac{3}{5}+5\frac{3}{4}-8\frac{3}{5}=\left(15\frac{3}{5}-8\frac{3}{5}\right)+5\frac{3}{4}=7+\frac{23}{4}=\frac{51}{4}\)

c) C = \(17\frac{1}{4}-\left(2\frac{3}{7}+7\frac{1}{4}\right)=17\frac{1}{4}-2\frac{3}{7}-7\frac{1}{4}=\left(17\frac{1}{4}-7\frac{1}{4}\right)-2\frac{3}{7}=10-\frac{17}{7}=\frac{53}{7}\)

d) D = \(\left(11\frac{5}{17}+3\frac{5}{7}\right)-4\frac{5}{17}=11\frac{5}{17}+3\frac{5}{7}-4\frac{5}{17}=\left(11\frac{5}{17}-4\frac{5}{17}\right)+3\frac{5}{7}=7+\frac{26}{7}=\frac{75}{7}\)

A) 11/125+(-17/18+4/9)-(5/7-17/14)

 =11/125+(-17/18+8/18)-(10/14-17/14)

=11/125+(-1/2)-(-1/2)

=11/125

B)(1+2+3+4-3-2-1)-(1/2+1/2+2/3+1/3+3/4+1/4)

 =4-3

=1

à bn lấy trong sách các dạng toán và phương pháp giải hả

1. TÍNH 

`5/7 xx 4 : 5/9 = 5/7 xx 4 xx 9/5 = 20/7 xx 9/5 = 36/7`

`4/9 : 2 xx 5/7 = 4/9 xx 1/2 xx 5/7 = 2/9 xx 10/63 `

`8 xx 2/3 : 1/2= 8xx 2/3 xx 2/1 = 8 xx 2/3 xx 2 = 16/3 xx 2=32/3`