Bài 4:
\(a.5\cdot2^2-18:3\\ =5\cdot4-6\\ =20-6\\ =14\\ b.17\cdot85+15\cdot17-2^3\cdot3\cdot5\\ =17\cdot\left(85+15\right)-8\cdot3\cdot5\\ =17\cdot100-120\\ =1700-120\\ =1580\\ c.2^3\cdot17-2^3\cdot14\\ =2^3\cdot\left(17-14\right)\\ =2^3\cdot3\\ =8\cdot3\\ =24\\ d.20-\left[30-\left(5-1\right)^2\right]\\ =20-\left(30-4^2\right)\\ =20-\left(30-16\right)\\ =20-14\\ =6\\ e.75-\left(3\cdot5^2-4\cdot2^3\right)\\ =75-\left(3\cdot25-4\cdot8\right)\\ =75-75+4\cdot8\\ =4\cdot8\\ =32\\ f.2\cdot5^2+3:71^0-54:3^3\\ =2\cdot25+3:1-54:27\\ =50+3-2\\ =50+1\\ =51\\ g.150+50:5-2\cdot3^2\\ =150+10-2\cdot9\\ =160-18\\ =142\\ h.5\cdot3^2-32:4^2\\ =5\cdot9-32:16\\ =45-2\\ =43\)
`#3107.101107`
`a)`
\(5\cdot2^2-18\div3\\ =5\cdot4-6\\ =20-6\\ =14\)
`b)`
\(17\cdot85+15\cdot17-2^3\cdot3\cdot5\\ =17\cdot\left(85+15\right)-8\cdot15\\ =17\cdot100-120\\ =1700-120\\ =1580\)
`c)`
\(2^3\cdot17-2^3\cdot14\\ =2^3\cdot\left(17-14\right)\\ =8\cdot3\\ =24\)
`d)`
\(20-\left[30-\left(5-1\right)^2\right]\\ =20-\left(30-4^2\right)\\ =20-\left(30-16\right)\\ =20-14\\ =6\)
`e)`
\(75-\left(3\cdot5^2-4\cdot2^3\right)\\ =75-\left(3\cdot25-4\cdot8\right)\\ =75-\left(75-32\right)\\ =75-75+32\\ =32\)
`f)`
\(2\cdot5^2+3\div71^0-54\div3^3\\ =2\cdot25+3\div1-54\div27\\ =50+3-2\\ =50+1\\ =51\)
`g)`
\(150+50\div5-2\cdot3^2\\ =150+10-2\cdot3^2\\ =160-2\cdot9\\ =160-18\\ =142\)
`h)`
\(5\cdot3^2-32\div4^2\\ =5\cdot9-32\div16\\ =45-2\\ =43\)
Bài 6:
a: \(5\cdot2^2-18:3\)
\(=5\cdot4-6\)
=20-6=14
b: \(17\cdot85+15\cdot17-2^3\cdot3\cdot5\)
\(=17\left(85+15\right)-8\cdot15\)
=1700-120
=1580
c: \(2^3\cdot17-2^3\cdot14=2^3\cdot\left(17-14\right)=2^3\cdot3=24\)
d: \(20-\left[30-\left(5-1\right)^2\right]\)
\(=20-\left[30-4^2\right]=20-14=6\)
e: \(75-\left(3\cdot5^2-4\cdot2^3\right)\)
\(=75-\left(3\cdot25-4\cdot8\right)\)
=75-75+32=32
f: \(2\cdot5^2+3:71^0-54:3^3\)
\(=2\cdot25+3-54:27\)
=50+3-2
=51
g: \(150+50:5-2\cdot3^2\)
=150+10-18
=160-18=142
h: \(5\cdot3^2-32:4^2\)
\(=5\cdot9-32:16\)
=45-2=43
Bài 7:
a: \(27\cdot75+25\cdot27-2\cdot3\cdot5^2\)
\(=27\cdot\left(75+25\right)-6\cdot25\)
\(=27\cdot100-150=2700-150=2550\)
b: \(12:\left\{400:\left[500-\left(125+25\cdot7\right)\right]\right\}\)
\(=12:\left\{400:\left[500-125-175\right]\right\}\)
\(=12:\left\{400:\left[500-300\right]\right\}=12:\left\{400:200\right\}\)
=12:2=6
c: \(13\cdot17-256:16+14:7-2021^0\)
=221-16+2-1
=205+1=206
d: \(2\cdot3^2:3+182+3\left(51:17\right)\)
\(=2\cdot3+182+3\cdot3=15+182=197\)
e: \(15-5^2\cdot2^3:\left(100\cdot2\right)\)
\(=15-25\cdot8:200=15-1=14\)
f: \(5^2\cdot2^3-12\cdot5+170:17-8\)
\(=25\cdot8-60+10-8\)
=120-60+2
=60+2
=62
