Đáp án:
Giải thích các bước giải:
bài 1
a)3/7+(-5/2)+(-3/5)
=30/70+(-175/70)+(-42/70)
=-145/70+(-42/70)
=-187/70
b)-8/18-15/27
=-4/9-5/9
=-1
c)4/5-(-2/7)-7/10
=4/5+2/7-7/10
=56/70+20/70-49/70
=76/70-49/70
=27/70
d)3,5-(-2/7)
=3,5+2/7
=7/2+2/7
=49/14+4/14
=53/14
Bài 2
a)(-6/21).3/2
=-3/7.1/1
=-3/7
b)(-3).(-7/2)
=21/2
c)(11/12÷33/16).3/5
=(11/12.16/33).3/5
=(1/3.4/3).3/5
=4/9.3/5
=12/45
d)√(-7)²+√25/16-3/2
=-7+5/4-3/2
=-28/4+5/4-6/4
=-23/4-6/4
=-29/4
e)1/2.√100-√1/16+(1/3)^0
=1/2.10-1/4+1
=5-1/4+1
=20/4-1/4+4/4
=23/4
Bài 3
a)(9/25-2.18)÷(3'4/5+0,2)
=(9/25-16)÷(19/5+1/5)
=(9/25-400/25) ÷4
=-391/25÷4
=-25/391.4
=-100/391
b)3/8.19'1/3-3/8.33'1/3
=3/8.58/3-3/8.100/3
=3/8.(58/3-100/3)
=3/8.(-14)
=-42/8
c)1'4/23+5/21-4/23+0,5+16/21
=(1'4/23-4/23)+(5/21+16/21)+0,5
=1+1+0,5
=2,5
Bài 4
a)21/47+9/45+26/47+4/5
=(21/47+26/47)+(9/45+4/5)
=1+(1/5+4/5)
=1+1
=2
b)15/12+5/13-3/12-18/3
=(15/12-2/12)+(5/13-18/13)
=1+(-1)
=0
c)13/25+6/41-38/25+35/41-1/2
=(23/25-38/25)+(6/41+35/41)-1/2
=-1+1-1/2
=-1/2
d)12.(-2/3)²+4/3
=12.4/9+4/3
=4.4/3+4/3
=16/3+4/3
=19/3
e)12,5.(-5/7)+1,5.(-5/7)
=-5/7.(12,5+1,5)
=-5,7.14
=-10
f)4/5.(7/2+1/4)²
=4/5.(14/4+1/4)²
=4/5.(15/4)²
=4/5.225/16
=1/1.45/4
=45/4
Bài 5
a)(3/7+1/2)²
=(6/14+7/14)²
=(13/14)²
=169/196
b)(3/4-5/6)²
=(9/12-10/12)²
=(-1/12)²
=1/144
c)5^4.20^4/25^5.4^5
=(5.20)^4/(25.4)^5
=100^4/100^5
=1/100
