Question

[đào bảo yến]

Answer 1

[Nguyễn Lê Phước Thịnh]

Bài 8:

a: \(2^3-5^3:5^2+12\cdot2^2\)

\(=8-5+12\cdot4\)

=3+48=51

b: \(5\cdot\left\lbrack\left(85-35:7\right):8+90\right\rbrack-5^2\cdot2\)

\(=5\cdot\left\lbrack\frac{\left(85-5\right)}{8}+90\right\rbrack-25\cdot2\)

\(=5\left(\frac{80}{8}+90\right)-50=5\left(10+90\right)-50=500-50=450\)

c: \(2\cdot\left\lbrack\left(7-3^3:3^2\right):2^2+99\right\rbrack-100\)

\(=2\cdot\left\lbrack\frac{\left(7-3\right)}{4}+99\right\rbrack-100\)

\(=2\left(1+99\right)-100=2\cdot100-100=100\)

d: \(2^7:2^2+5^4:5^3\cdot2^4-3\cdot2^5\)

\(=2^5+5\cdot2^4-3\cdot32\)

=32+80-96

=32-16

=16

e: \(\left(3^5\cdot3^7\right):3^{10}+5\cdot2^4-7^3:7\)

\(=\frac{3^{12}}{3^{10}}+5\cdot16-7^2\)

=9+80-49

=80-40=40

f: \(3^2\cdot\left\lbrack\left(5^2-3\right):11\right\rbrack-2^4+2\cdot10^3\)

\(=9\cdot\left\lbrack\frac{25-3}{11}\right\rbrack-16+2\cdot1000\)

\(=9\cdot\frac{22}{11}-16+2000=18-16+2000=2002\)

g: \(\left(6^{2007}-6^{2006}\right):6^{2006}\)

\(=\frac{6^{2007}}{6^{2006}}-\frac{6^{2006}}{6^{2006}}\)

=6-1=5

h: \(\left(5^{2001}-5^{2000}\right):5^{2000}\)

\(=\frac{5^{2001}}{5^{2000}}-\frac{5^{2000}}{5^{2000}}\)

=5-1=4

i: \(\left(7^{2005}+7^{2004}\right):7^{2004}\)

\(=\frac{7^{2005}}{7^{2004}}+\frac{7^{2004}}{7^{2004}}\)

=7+1=8

j: \(\left(5^7+7^5\right)\cdot\left(6^8+8^6\right)\left(2^4-4^2\right)\)

\(=\left(5^7+7^5\right)\left(6^8+8^6\right)\left(16-16\right)\)

\(=\left(5^7+7^5\right)\left(6^8+8^6\right)\cdot0=0\)

k: \(\left(7^5+7^9\right)\left(5^4+5^6\right)\cdot\left(3^3\cdot3-9^2\right)\)

\(=\left(7^5+7^9\right)\left(5^4+5^6\right)\left(3^4-3^4\right)\)

\(=\left(7^5+7^9\right)\left(5^4+5^6\right)\cdot\left(81-81\right)=0\)

l: \(\left\lbrack\left(5^2\cdot2^3-7^2\cdot2\right):2\right\rbrack\cdot6-7\cdot2^5\)

\(=\left\lbrack\left(25\cdot8-49\cdot2\right):2\right\rbrack\cdot6-7\cdot32\)

\(=\left(200-98\right):2\cdot6-224\)

\(=\frac{102}{2}\cdot6-224=51\cdot6-224=82\)

Bài 7:

a: \(27\cdot75+25\cdot27-2\cdot3\cdot5^2\)

\(=27\left(75+25\right)-6\cdot25\)

\(=27\cdot100-150=2700-150=2550\)

b: \(12:\left\lbrace400:\left\lbrack500-\left(125+25\cdot7\right)\right\rbrack\right\rbrace\)

\(=12:\left\lbrace400:\left\lbrack500-125-175\right\rbrack\right\rbrace\)

\(=12:\left\lbrace400:\left(500-300\right)\right\rbrace\)

\(=12:\left\lbrace400:200\right\rbrace=\frac{12}{2}=6\)

c: \(13\cdot17-256:16+14:7-2021^0\)

=221-16+2-1

=220-14

=206

d: \(2\cdot3^2:3+182+3\cdot\left(51:17\right)\)

\(=2\cdot3+182+3\cdot3=6+9+182=182+15=197\)

e: \(15-5^2\cdot2^3:\left(100\cdot2\right)\)

\(=15-25\cdot8:200\)

=15-1=14

f: \(5^2\cdot2^3-12\cdot5+170:17-8\)

\(=25\cdot8-60+10-8\)

=200-60+2

=140+2

=142