1. Tìm x, biết:
a) 3,2.x + (-1,2).x + 2,7 = -4,9
b) -5,6.x + 2,9.x - 3,86 = -9,8
2. Tính giá trị của các biểu thức :
A = -5,13 : \(\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
B = \(\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
Bài 1:
a) Ta có:
\(3,2\cdot x+\left(-1,2\right)\cdot x+2,7=-4,9\)
\(\Rightarrow\left[3,2+\left(-1,2\right)\right]\cdot x=\left(-4,9\right)-2,7\)
\(\Rightarrow2x=-7,6\)
\(\Rightarrow x=\left(-7,6\right):2\)
\(\Rightarrow x=-3,8\)
Vậy \(x=-3,8\)
b) Ta có:
-5,6.x+2,9.x-3,86=-9,8
=>[(-5,6)+2,9].x=(-9,8)+3,86
=>(-2,7).x=-5,94
=>x=(-5,94):(-2,7)
=>x=2,3
Vậy x=2,2
1. Tìm x
a) 3,2. x + (-12).x + 2,7 = -4,9
b) -5,6.x + 2,9.x -3,86= -9,8
2. tính Giá trị
A= -5,13:\(\left(5\dfrac{5}{28}-1\dfrac{8}{9}.1.25+1\dfrac{16}{63}\right)\)
B= \(\left(3\dfrac{1}{3}.1,9+19,5:4\dfrac{1}{3}\right).\left(\dfrac{62}{75}-\dfrac{4}{25}\right).\)
1,
a) 3,2x +(-12)x +2,7=-4,9 b)-5,6x+2,9x-3,86=-9,8
=>3,2x+(-12)x=-4,9-2,7 =>-5,6x+2,9x=-9,8+3,86
=>3,2x+(-12)x=-7,6 =>-5,6x+2,9x=-5,94
=>x[3,2+(-12)]=-7,6 =>x[(-5,6)+2,9]=-5,94
=>2x=-7,6=>x=-7,6:2=-3,8 =>-2,7x=-5,94=>x=(-5,94):(-2,7)=2,2
tính giá trị biểu thức :
a) \(A=-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
b) \(B=\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
Tính giá trị của các biểu thức:
a) \(-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
b) \(\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
GIẢI ĐẦY ĐỦ BÀI NÀY GIÚP MK VS MK CẦN RẤT GẤP!
Tinh:
A=-5,13:\(\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
B=\(\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right)\).\(\left(\frac{62}{75}-\frac{4}{25}\right)\)
Tính giá trị của các biểu thức:
a) \(-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
b) \(\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
GIẢI ĐẦY ĐỦ GIÚP MK VS , MK ĐANG CẦN RẤT GẤP!
Tính giá trị của các biểu thức:
a) \(-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
b) \(\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
GIẢI ĐẦY ĐỦ GIÚP MK BÀI NÀY VS , MK CAANF RẤT GẤP!
a) \(-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
\(=-5,13:\left(\frac{145}{28}-\frac{17}{9}.1,25+\frac{79}{63}\right)\)
\(=-5,13:\left(\frac{145}{28}-\frac{85}{36}+\frac{79}{63}\right)\)
\(=-5,13:\frac{57}{14}\)
\(=-\frac{63}{50}\)
b) \(\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}.\left(\frac{62}{75}-\frac{4}{25}\right)\right)\)
\(=\left(\frac{10}{3}.1,9+19,5:\frac{13}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
\(=\left(\frac{19}{3}+\frac{9}{2}\right).\frac{2}{3}\)
\(=\frac{65}{6}.\frac{2}{3}\)
\(=\frac{65}{9}\)
^...^ 
^_^
a) -5,13:(5/5/28-85/36+1/16/63)
-5,13:(355/126+79/63)
-5,13:57/14
=-126
B(19/3+9/2).2/3
65/6.2/3
= 65/9
A = \(\left(-1+3\frac{2}{5}+\frac{1}{4}\right):\left(-4\right)\)
B = \(\left(0,645:0,3-1\frac{17}{150}\right):\left(4:6,25-\frac{1}{5}+\frac{1}{7}.1,96\right)-11,125\)
C=\(11,26-5,13:[5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}]\)
-5,6x + 2,9x - 3,86=-9,8
A=-5,13 : (\(5\frac{5}{28}\)trừ \(1\frac{8}{9}\)
nhân 1,25 cộng\(1\frac{16}{63}\))
B=(\(3\frac{1}{3}\)nhân 1,9 + 19,5 : \(4\frac{1}{3}\)) . (\(\frac{62}{75}\)_ \(\frac{4}{25}\))
\(-5,6x+2,9x-3,86=-9,8\)
\(-2,7x=-9,8+3,86\)
\(-2,7x=-5,94\)
\(x=-5,94:\left(-2,7\right)\)
\(x=2,2\)
\(A=-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
\(A=-5,13:\left(\frac{145}{28}-\frac{17}{9}.\frac{5}{4}+\frac{79}{63}\right)\)
\(A=-5,13:\left(\frac{145}{28}-\frac{85}{36}+\frac{79}{63}\right)\)
\(A=-5,13:\left(\frac{355}{126}+\frac{79}{63}\right)\)
\(A=-5,13:\frac{57}{14}\)
\(A=-1,26=\frac{-63}{50}\)
\(B=\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
\(B=\left(\frac{10}{3}.\frac{19}{10}+\frac{39}{2}.\frac{3}{13}\right).\frac{2}{3}\)
\(B=\left(\frac{19}{3}+\frac{9}{2}\right).\frac{2}{3}\)
\(B=\frac{65}{6}.\frac{2}{3}\)
\(B=\frac{65}{9}\)
học tốt
