2+12*74=?
so sánh
a ) 1 2 − 7 4 v à − 1 ; b ) 1 2 − − 7 4 + 13 8 v à 2 ; c ) 5 2 − 1 14 v à 3 2 − 6 7 ; d ) 3 4 + 7 − 15 − − 5 6 v à 7 10 − 2 15 .
a ) − 5 4 < − 1. b ) 31 8 > 2. c ) 9 14 < 17 7 . d ) 67 60 > 1 10
Tính:
a) 2 3 + 1 2 - 1 10
b) 4 1 7 : 7 4
a) 2 3 + 1 2 - 1 10 = 20 30 + 15 30 − 3 30 = 20 + 15 − 3 30 = 16 15
b) 4 1 7 : 7 4 = 17 4 : 7 4 = 17 4 × 4 7 = 17 7
Tìm x, biết:
a ) 2 | x | − 1 2 = 3 4 b ) 2 x − 1 3 + 5 6 = 1 c ) 1 2 − 3 x + 4 1 5 = 6 2 5 d ) 17 2 − 2 x − 3 4 = − 7 4
Chú ý rằng |a| = b với b > 0 thì a = b hoặc a = - b.
a ) x ∈ − 5 8 ; 5 8 b ) x ∈ 1 12 ; 1 4
c ) x ∈ − 17 30 ; 9 10 d ) x ∈ − 19 4 ; 11 2
bài 1: tính
1/12 x 4/5
9/5 : 4/7
4 x 3/7
1/2 : 5
\(\dfrac{1}{12}\times\dfrac{4}{5}=\dfrac{4}{60}=\dfrac{1}{15}\\ \dfrac{9}{5}:\dfrac{4}{7}=\dfrac{9}{5}\times\dfrac{7}{4}=\dfrac{63}{20}\\ 4\times\dfrac{3}{7}=\dfrac{4\times3}{7}=\dfrac{12}{7}\\ \dfrac{1}{2}:5=\dfrac{1}{2}\times\dfrac{1}{5}=\dfrac{1}{10}\)
Điền dấu + hoặc -.
67...12...112..85....74 = 178
89....74 = 15
67-12+112+85-74=178
89-74=15
1) 67 -12 + 112 +85 - 74 = 178
2) 89 - 74 = 15
ủng hộ nha
67 - 12 + 112 + 85 - 74 = 178 .
89 - 74 = 15 .
2^4.3+338:(6.x-5)^2=5^2.2
3^4-120:[16-12.(3.x-74)]=3.7
^ là mũ
a: =>48+338:(6x-5)^2=50
=>338:(6x-5)^2=2
=>(6x-5)^2=169
=>6x-5=13 hoặc 6x-5=-13
=>6x=-8 hoặc 6x=18
=>x=3 hoặc x=-4/3
b: =>120:[16-12(3x-74)]=81-21=60
=>16-12(3x-74)=2
=>12(3x-74)=14
=>3x-74=7/6
=>x=451/18
2^4.3+338:(6.x-5)^2=5^2.2
3^4-120:[16-12.(3.x-74)]=3.7
^ là mũ
a: =>338:(6x-5)^2=25*2-48=2
=>(6x-5)^2=169
=>6x-5=13 hoặc 6x-5=-13
=>x=-4/3 hoặc x=3
b: =>120:[16-12(3x-74)]=81-21=60
=>16-12(3x-74)=2
=>12(3x-74)=14
=>3x-74=7/6
=>3x=451/6
=>x=451/18
74/12x12/10x12/12=
`74/12xx12/10xx12/12`
`=37/6xx6/5xx1`
`=37/5`
Tính: 2 3 - - 7 4 - 1 2 + 3 8