Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(a.6,5+1,2+3,5-5,2+6,5-4,8
\)
\(=\left(6,5+3,5\right)+\left(1,2+6,5\right)-\left(5,2+4,8\right)\)
\(=10+7,7-10\)
\(=\left(10-10\right)+7,7\)
\(=0+7,7=7,7\)
bài 2)
a)|12,1x+12,1.0,1|=12,1
<=> |12,1(x+0,1)|=12,1
<=>\(\left[\begin{array}{nghiempt}12,1\left(x+0,1\right)=12,1\\12,1\left(x+0,1\right)=-12,1\end{array}\right.\)
<=> \(\left[\begin{array}{nghiempt}x=0,9\\x=-1,1\end{array}\right.\)
b) |0,2x-3,1|+|0,2+3,1|=0
<=>|0,2x-3,1|+3,3=0
ta có |A|>=0
=> pt trên vô nghiệm
bài 1) a) 6,5+1,2+3,5-5,2+6,5-4,8
=(6,5+3,5+6,5)-(5,2-1,2+4,8)
=15,5-8,8=24,6
tt nha bạn
1. Tính nhanh
a) 6,5+1,2+3,5-5,2+6,5-4,8
= 6,5+1,5+3,5+6,5-5,2-4,8
= (6,5+3,5+6,5)+1,2-(5,2+4,8)
= 16,5+1,2-10
= 17,7-10
=7,7
b) (-4,3.1,1+1,1.4,5):(-0,5:0,05+10,01)
= {1,1.[(-4,3)+4,5)} : [(-10)+10,01]
= ( 1,1.0.2 ) : 0,01
= 1,1 : 5 . 100
= 1,1 . 20
= 22
c) (6,7+5,66-3,7+4,34).(-76,6.1,2+7,66.12)
= [(5,66+4,34)+(6,7-3,7)]. [ 7,66. (-10).1,2+7,66.12)]
= ( 10+ 3) . [7,66.(-12)+7,66.12]
= 13. { 7,66. [ (-12)+12]}
= 13. (7,66 . 0)
= 13
2. So sánh x và y
x= (42-4,2.10+76:7,6):(0,01.0,1)
y=(689,7+0,3):(7,4:0,2-2,2-1,5)
Giải
Ta có: x= (42-4,2.10+76:7,6):(0,01.0,1)
=> x= ( 42-42 + 10 ) : 0,001
=> x= 10 : 0,001
=> x= 10.1000
=> x= 10000 (1)
Lại có: y=(689,7+0,3):(7,4:0,2-2,2-1,5)
=> y= 690: ( 37-2,2-1,5)
=> y= 690 : 33,3 (2)
Từ (1) và (2) => x > y
a) \(6,5+1,2+3,5-5,2+6,5-4,8\)
\(=6,5+1,2+3,5+6,5-5,2-4,8\)
\(=\left(6,5+3,5+6,5\right)+1,2-\left(5,2+4,8\right)\)
\(=16,5+1,2-10\)
\(=17,7-10\)
\(=7,7.\)
b) \(\left(-4,3.1,1+1,1.4,5\right):\left(-0,5:0,05+10,01\right)\)
\(=\left\{1,1.\left[\left(-4,3\right)+4,5\right]\right\}:\left[\left(-10\right)+10,01\right]\)
\(=\left(1,1.0,2\right):0,01\)
\(=0,22:0,01\)
\(=22.\)
c) \(\left(6,7+5,66-3,7+4,34\right).\left(-76,6.1,2+7,66.12\right)\)
\(=\left[\left(5,66+4,34\right)+\left(6,7-3,7\right)\right].\left[7,66.\left(-10\right).1,2+7,66.12\right]\)
\(=\left[10+3\right].\left[7,66.\left(-12\right)+7,66.12\right]\)
\(=13.\left\{7,66.\left[\left(-12\right)+12\right]\right\}\)
\(=13.0\)
\(=0.\)
Chúc bạn học tốt!
( 6,7 + 5,66 - 3.7 +4,34 ).( -76,6 .1,2 +7,66 .12 )
= [( 6,7 -3,7 ) + ( 5,66 + 4,34 )].[ -7,66 . 12 + 7,66 . 12 )
= ( 3 + 10 ).[ 12 . ( -7,66 + 7,66 )]
= 13 . 0
= 0
\(\left(6,7-5,66-3,7+4,34\right)\cdot\left(-76,6\cdot1,2+7,66\cdot12\right)\)
\(=\left[\left(6,7-3,7\right)+\left(5,66+4,34\right)\right]\left[-7,66\cdot12+7,66\cdot12\right]=\left(3\cdot10\right)\cdot0=0\)
1) Tính nhanh
a) \(6,5+1,2+3,5-5,2+6,5-4,8\)
\(=\left(6,5+3,5\right)-\left(5,2+4,8\right)+\left(1,2+6,5\right)\)
\(=10-10+7,7\)
\(=7,7\)
a/ \(6,5+1,2+3,5-5,2+6,5-4,8\)
\(=\left(6,5+3,5+6,5\right)+1,2-\left(5,2+4,8\right)\)
\(=16,5+1,2-10\)
\(=17,7-10=7,7\)
b/ \(\left(-4,3.1,1+1,1.4,5\right):\left(-0,5:0,05+10,01\right)\)
\(=1,1\left(-4,3+4,5\right):\left(-10+10,01\right)\)
\(=1,1.0,2:0,01\)
\(=1,1.20=22\)
c/ \(\left(6,7+5,66-3,7+4,34\right).\left(-76,6.1,2+7,66.12\right)\)
\(=\left[\left(5,66+4,34\right)+\left(6,7-3,7\right)\right]\left[7,66.\left(-10\right).1,2+7,66.12\right]\)
\(=\left(10+3\right).\left[7,66\left(-12\right)+7,66.12\right]\)
\(=13.0=0\)
\(\text{6,5+ 1,2+3,5-5,2+6,5-4,8}=\left(6,5+3,5\right)+\left(-5,2-4,8\right)+\left(1,2+6,5\right)\)
=10-10+7,7=7,7
\(\text{(-4,3.1,1+1,1.4,5): (-0,5:0,05+10,01)}=\dfrac{1,1.\left(-4,3+4,5\right)}{-10+10,01}=\dfrac{0,22}{0,01}=22\)
\(\text{(6,7+5,66-3,7+4,34). (-76,6.1,2+7,66.12)}\)
=(6,7+5,66-3,7+4,34)(-76,6.1,2+76,6.1,2)=0