\(\frac{0,3}{x}+\frac{0,8}{x}=1,6\)
Tìm nghiệm các đa thức sau
B(x)= x - (0,7-x)2 - 0,7
C(x)= \(\frac{4x-3}{6}-\frac{5-3x}{3}+\frac{1}{3}\)
D(x)= 1,1+ (x-0,8)2 - (x+0,3)
Chứng tỏ rằng đa thức M(x)= |x2+5| - 7x -8 vô nghiệm
\(C\left(x\right)=\frac{4x-3}{6}-\frac{5-3x}{3}+\frac{1}{3}\)
\(\frac{4x-3}{6}-\frac{5-3x}{3}+\frac{1}{3}=0\)
\(4x-3-2\left(5-3x\right)+2=0\)
\(4x-1-2\left(5-3x\right)=0\)
\(4x-1-10+6x=0\)
\(10x-11=0\)
\(10x=0+11\)
\(10x=11\)
\(x=\frac{11}{10}\)
Bài 1 : Tìm X
a) \(\frac{2xX-4,36}{0,125}=\)0,25 x 42,9 - 11,7 x 0,25 + 0,25 x 0,8
b) 104,5 x X -14,1 x X + 9,6 x X = 25
c) \(\frac{5xX}{x-13}=\)49 x 0,5 - 7 x 0,5 + 0,25
d) 13,44 x X - ( 1,6 + x ) x 0,5 -3,7 x ( x - 0,9 ) = 13, 618
#)Giải :
a) \(\frac{2xX-4,36}{0,125}=\)0,25 x 42,9 - 11,7 x 0,25 + 0,25 x 0,8
\(\frac{2xX-4,36}{0,125}=\)0,25 x ( 42,9 - 11,7 + 0,8 )
\(\frac{2xX-4,36}{0,125}=\)0,25 x 32
\(\frac{2xX-4,36}{0,125}=8\)
\(2xX-4,36=8x0,125\)
\(2xX-4,36=1\)
\(2xX=1+4,36\)
\(2xX=5,36\)
\(X=5,36:2\)
\(X=2,68\)
#~Will~be~Pens~#
#)Next :
b) 104,5 x X - 14,1 x X + 9,6 x X = 25
( 104,5 - 14,1 + 9,6 ) x X = 25
100 x X = 25
X = 25 : 100
X = 0,25
#~Will~be~Pens~#
b,
104,5.x-14,1.x+9,6.x=25
x(104,5-14,1+9,6)=25
x.100=25
x=25:100
x=0,25
tình thuận tiện 0,8 x 96 + 1,6 x 2 + 1,6 x 50
0,8 x 96 + 1,6 x 2 + 1,6 x 5
= 0,8 x 96 + 0,8 x 2 x 2 + 0,8 x 2 x 5
= 0,8 x 96 + 0,8 x 4 + 0,8 x 10
= 0,8 x (96 + 4 + 10)
= 0,8 x 110
= 88
2,8 + 1,6 x 0 ,5 : 2 =
1,5 + 0,8 x 5dm :2=
\(\frac{1}{3}\)+ \(\frac{1}{5}\)x \(\frac{1}{2}\): 2
giải được mình tick cho
tìm x biết:
a,\(\left(\frac{1}{3}.x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)
b,\(4,5:0,3=2,25:\left(0,1.x\right)\)
c,\(8:\left(\frac{1}{4}.x\right)=2:0,02\)
d,\(3:2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)
e,\(3,8:\left(2.x\right)=\frac{1}{4}:2\frac{2}{3}\)
f,\(\left(0,25.x\right):3=\frac{5}{6}:0,125\)
g,\(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0.1.x\right)\)
làm 1 bài mẫu nha
a) \(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{25}{6}\)
\(\Rightarrow\frac{1}{3}x=\frac{25}{9}\)
\(\Rightarrow x=\frac{25}{9}:\frac{1}{3}\)
\(\Rightarrow x=\frac{25}{3}\)
các bài sau dễ lắm
a) \(\left(\frac{1}{3}x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)
\(\Rightarrow\frac{1}{3}x:\frac{2}{3}=\frac{25}{6}\)
\(\Rightarrow\frac{1}{3}x=\frac{5}{3}\)
\(\Rightarrow x=\frac{5}{3}:\frac{1}{3}\)
\(\Rightarrow x=5\)
a) \(\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)
\(\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=\frac{25}{6}\)
\(\frac{1}{3}x=\frac{25}{6}\cdot\frac{2}{3}\)
\(\frac{1}{3}x=\frac{25}{9}\)
\(x=\frac{25}{9}:\frac{1}{3}\)
\(x=\frac{25}{3}\)
b) \(4,5:0,3=2,25:\left(0,1x\right)\)
\(15=2,25:\left(0,1x\right)\)
\(2,25:15=0,1x\)
\(0,15=0,1x\)
\(0,15:0,1=x\)
\(1,5=x\)
c) \(8:\left(\frac{1}{4}\cdot x\right)=2:0,02\)
\(8:\left(\frac{1}{4}\cdot x\right)=100\)
\(\frac{1}{4}\cdot x=8:100\)
\(\frac{1}{4}\cdot x=0,08\)
\(x=0,08:\frac{1}{4}\)
\(x=0,32\)
d) \(3:2\frac{1}{4}=\frac{3}{4}:\left(6\cdot x\right)\)
\(\frac{4}{3}=\frac{3}{4}:\left(6\cdot x\right)\)
\(\frac{3}{4}:\frac{4}{3}=6\cdot x\)
\(\frac{9}{16}=6\cdot x\)
\(\frac{9}{16}:6=x\)
\(\frac{3}{32}=x\)
e) \(3,8:\left(2\cdot x\right)=\frac{1}{4}:2\frac{2}{3}\)
\(3,8:\left(2\cdot x\right)=\frac{3}{32}\)
\(2\cdot x=3,8:\frac{3}{32}\)
\(2\cdot x=\frac{608}{15}\)
\(x=\frac{608}{15}:2\)
\(x=\frac{304}{15}\)
f) \(\left(0,25\cdot x\right):3=\frac{5}{6}:0,125\)
\(\left(0,25\cdot x\right):3=\frac{20}{3}\)
\(0,25\cdot x=\frac{20}{3}\cdot3\)
\(0,25\cdot x=20\)
\(x=20:0,25\)
\(x=80\)
g) \(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0,1\cdot x\right)\)
\(\frac{5}{3}=\frac{2}{3}:\left(0,1\cdot x\right)\)
\(\frac{2}{3}:\frac{5}{3}=0,1\cdot x\)
\(\frac{2}{5}=0,1x\)
\(\frac{2}{5}:0,1=x\)
\(4=x\)
(Nhớ thử lại kết quả nhé)
Câu 10: Tính bằng cách thuận tiện
0,8 x 2 x 48 +1,6 x 2 + 1,6 x 50
\(=\left(0,8\times2\right)\times48+1,6\times2+1,6\times50\\ =1,6\times48+1,62\times+1,6\times50\\ =1,6\times\left(48+2+50\right)\\ =1,6\times100\\ =160\)
= (0,8 × 2) × 48 + 1,6 × 2 + 1,6 × 50
= 1,6 × 48 + 1,6 × 2 + 1,6 × 50
= 1,6 × (48 + 2 + 50)
= 1,6 × 100
= 160
Tính bằng cách thuận tiện nhất : 0,8 x 96 + 1,6 + 20 x 1,6
tính
\(\frac{-1}{3}+\frac{0,2-0,3+\frac{5}{11}}{-0,3+\frac{9}{16}-\frac{15}{12}}\)
tìm x :
\(\frac{29-x}{21}+\frac{27-x}{23}+\frac{25-x}{25}+\frac{23-x}{27}+\frac{21-x}{29}=0\)
giúp mình nhé thanks
29-x/21 + 27-x/23 + 25-x/25 + 23-x/27 + 21-x/29 = -5
1 + 29-x/21 + 1 + 27-x/23 + 1 + 25-x/25 + 1 + 23-x/27 + 1 + 21-x/29 = 0
50-x/21 + 50-x/23 + 50-x/25 + 50-x/27 + 50-x/29 = 0
(50-x) (1/21 + 1/23 + 1/25 + 1/27 + 1/29) = 0
Vì: 1/21 + 1/23 + 1/25 + 1/27 + 1/2 > 0
=> 50 - x = 0
x = 50
Vậy x = 50
\(\frac{-1}{3}+\frac{0,2-0,3+\frac{5}{11}}{-0,3+\frac{9}{16}-\frac{15}{12}}\)
\(=\frac{-1}{3}+\frac{\frac{2}{10}-\frac{3}{10}+\frac{5}{11}}{\frac{-3}{10}+\frac{9}{16}-\frac{15}{12}}\)
\(=\frac{-1}{3}+\frac{\frac{39}{110}}{\frac{-79}{80}}\)
\(=\frac{-1}{3}-\frac{312}{869}\)
\(=\frac{-1805}{2607}\)
Tính bằng cách thuận tiện nhất :
62 x 1,6 + 0,8 x 30 + 1,6 x 23
\(62\times1,6+0,8\times30+1,6\times23\)
\(=62\times1,6+24+1,6\times23\)
\(=1,6\times\left(62+23+24\right)\)
\(=1,6\times110\)
\(=176\)
62 x 1,6 + 0,8 x 30 + 1,6 x 23
= 62 x 1,6 + 24 + 1,6 x 23
= 1,6 x ( 62 + 23 + 24 )
= 1,6 x 110
= 176