p(x)= (x+2)+(x+5)+(x+7)+...+(x+152)-154
Tìm x, biết:
a ) | x | − 3 4 = 5 3 ; b ) x − 3 2 = 1
c ) x − 3 2 + 11 4 = 15 4 ; d ) 17 4 − 5 6 − x = − 7 4 e ) x + 1 5 2 − 9 25 = 0 ; f ) x + 1 5 2 + 17 25 = 26 25
a ) | x | − 3 4 = 5 3 = > | x | = 29 12 = > x = 29 12 x = − 29 12
b) x − 3 2 = 1 = > x − 3 2 = 1 x − 3 2 = − 1 = > x = 5 2 x = 1 2
c) x − 3 2 + 11 4 = 15 4 = > x − 3 2 = 1 = > x = 5 2 x = 1 2
d) 17 4 − 5 6 − x = − 7 4 = > 5 6 − x = 6 = > x = − 31 6 x = 41 6
e)
x + 1 5 2 − 9 25 = 0 = > x + 1 5 2 = 9 25 = > x + 1 5 = 3 5 x + 1 5 = − 3 5 = > x = 2 5 x = − 4 5
f) x + 1 5 2 + 17 25 = 26 25 = > x + 1 5 2 = 9 25 = > x = 2 5 x = − 4 5
154+153+152+...+x=154
x+143/157+x+146/154=x+149/151+x+152/148 Các bạn giúp mình với!!
\(\frac{x+143}{157}+\frac{x+146}{154}=\frac{x+149}{151}+\frac{x+152}{148}\)
\(\Leftrightarrow\frac{x+143}{157}+1+\frac{x+146}{154}+1=\frac{x+149}{151}+1+\frac{x+152}{148}+1\)
\(\Leftrightarrow\frac{x+300}{157}+\frac{x+300}{154}=\frac{x+300}{151}+\frac{x+300}{148}\)
\(\Leftrightarrow\left(x+300\right)\left(\frac{1}{157}+\frac{1}{154}-\frac{1}{151}-\frac{1}{148}\right)=0\)
có \(\frac{1}{157}+\frac{1}{154}+\frac{1}{151}+\frac{1}{148}\ne0\)
\(\Leftrightarrow x+300=0\)
\(\Leftrightarrow x=-300\)
Bµi 1 1 37064 – 64 x 82 42966 217 2 320 – 120.5 95,25 5,25 874 12 x 12,53 132 x 9 132 4 48 x 17 48 x 3 5 56 x 27 56 x 35 62 6 45 x 48 – 90 x 24 145 7 754 x 75 – 2262 x 25 4568 8 1050 15 – 350 5 1769 4320 9 – 8640 18 750 10 316 192 384 321 108 11 24 25 26 ….. 124 125 126 12 154 – 153 152 – 151 150 – 149 ….. 4 – 3 2 – 113 37 x 38 – 19 x 74 1000 14 0.48 x 500 – 2.4 x 40 x 2
Tìm x thuộc Z, biết:
a) 1 2 + 1 3 + 1 6 ≤ x ≤ 15 4 + 18 8
b) 11 3 + − 19 6 + − 15 2 ≤ x ≤ 19 12 + − 5 4 + − 10 3
a) 1 ≤ x ≤ 6 ⇒ x ∈ - 3 ; - 2 ; - 1 ; 0 ; 1
b) - 7 ≤ x ≤ - 3 ⇒ x ∈ - 3 ; - 2 ; - 1 ; 0 ; 1
Tìm x ∈ ℤ ,biết:
a ) 5 3 + − 14 3 < x < 8 5 + 4 10 ; b ) 5 21 + − 3 7 < x 21 < − 2 7 + 8 21 ;
c ) 1 2 + 1 3 + 1 6 ≤ x ≤ 15 4 + 18 8 ; d ) 11 3 + − 19 6 + − 15 2 ≤ x ≤ 19 12 + − 5 4 + − 10 3
a) – 3 < x < 2 => x ∈ {-2;-1;0;1}
b) − 4 21 < x 21 < 2 21 => x ∈ {-3;-2;-1;0;1}
c) 1 ≤ x ≤ 6 => x ∈ {-3;-2;-1;0;1}
d) -7 ≤ x ≤ -3 => x ∈ {-3;-2;-1;0;1}
Tính bằng cách thuận tiên nhất:
1):(3/4 x 5/97 + 1/9 x 13/47) x (1/5 - 7/25 x 5/7)
2): 8/17 x 4/15 + 8/17 x 22/15 - 8/15 x 9/17
3): 2021/2 x 1/3 + 4042/4 x 1/5 + 6063/3 x 22/15
4); 4/7 x 2/13 + 8/13 :7/4 + 4/7 : 13/2 + 4/7 x 1/13
5): 2022 x 2021 - 1/ 2021 + 2022 x 2020
6): 18 x 123 + 9 x 4567 x 2 + 3 x 5310 x 6 / (2 + 4 + 6 + 8 + ...+20 + 22) + 48
7): A= 2021 x 2021 x 202020 - 2020 x 2020 x 20212021 / 2020 x 20192019
1) Ta có: \(\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{7}{25}\cdot\dfrac{5}{7}\right)\)
\(=\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{1}{5}\right)\)
=0
2) Ta có: \(\dfrac{8}{17}\cdot\dfrac{4}{15}+\dfrac{8}{17}\cdot\dfrac{22}{15}-\dfrac{8}{15}\cdot\dfrac{9}{17}\)
\(=\dfrac{8}{17}\left(\dfrac{4}{15}+\dfrac{22}{15}-\dfrac{9}{15}\right)\)
\(=\dfrac{8}{17}\cdot\dfrac{15}{15}=\dfrac{8}{17}\)
3) Ta có: \(\dfrac{2021}{2}\cdot\dfrac{1}{3}+\dfrac{4042}{4}\cdot\dfrac{1}{5}+\dfrac{6063}{3}\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)+2021\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{8}{15}+\dfrac{2021}{2}\cdot\dfrac{44}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{52}{15}\)
\(=\dfrac{52546}{15}\)
4) Ta có: \(\dfrac{4}{7}\cdot\dfrac{2}{13}+\dfrac{8}{13}:\dfrac{7}{4}+\dfrac{4}{7}:\dfrac{13}{2}+\dfrac{4}{7}\cdot\dfrac{1}{13}\)
\(=\dfrac{4}{7}\left(\dfrac{2}{13}+\dfrac{8}{13}+\dfrac{2}{13}+\dfrac{1}{13}\right)\)
\(=\dfrac{4}{7}\)
(2x-5)3=152-4.52
(x-2)(15-3x)=0
(x-5)-(2x+7)= -8
a: \(\Leftrightarrow\left(2x-5\right)^3=225-4\cdot100=125\)
=>2x-5=5
=>2x=10
hay x=5
b: \(\Leftrightarrow\left(x-2\right)\left(x-5\right)=0\)
hay \(x\in\left\{2;5\right\}\)
c: =>x-5-2x-7=-8
=>-x-12=-8
=>x+12=8
hay x=-4
\(\left(2x-5\right)^3=15^2-4.5^2\)
\(\Leftrightarrow\left(2x-5\right)^3=125\)
\(\Leftrightarrow2x-5=5\)
\(\Leftrightarrow x=5\)
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\(\left(x-2\right)\left(15-3x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\15-3x=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=5\end{matrix}\right.\)
____________________________________________
\(\left(x-5\right)-\left(2x+7\right)=-8\)
\(\Leftrightarrow x-5-2x-7=-8\)
\(\Leftrightarrow-x=4\)
\(\Leftrightarrow x=-4\)
tìm x thuộc Z:
a, -154+(x-9-18)=40
b,/9-x/=64+(-7)
c, -(-x+13.142)+18=55
d,(x-7).(x+1)=0
e,(x-7).(x+1)>0
f, (x-3).(x^2+5)=0
a, -154+(x-9-18)=40
x-27=40-(-154)
x-27=194
x=194+27
x=221
b,\(\left|9-x\right|\)=64+(-7)
\(\left|9-x\right|\)=57
TH1:
9-x=57
x=9-57
x=-48
TH2:
9-x=-57
x=9-(-57)
x=66
a, -154+(x-9-18)=40
x-27=40-(-154)
x-27=194
x=194+27
x=221
b,|9−x||9−x|=64+(-7)
|9−x||9−x|=57
TH1:
9-x=57
x=9-57
x=-48
TH2:
9-x=-57
x=9-(-57)
x=66