15 x 2 = ?
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TL :
( 15 x 15 ) : 2 x ( 15 x 15 ) : 2 x ( 15 x 15 ) : 2 + ( 0 + 1 + 2 + 2 + 3 + 45 ) x 0
= 0
=> vì : tất cả số nào nhân vs 0 đều = 0
_HT_
`@` `\text {Ans}`
`\downarrow`
`a)`
`x + 10 = 20`
`=> x = 20 -10`
`=> x = 10`
Vậy, `x = 10`
`b)`
`2 * x + 15 = 35`
`=> 2x = 35 - 15`
`=> 2x = 20`
`=> x = 20 \div 2`
`=> x = 10`
Vậy, `x = 10`
`c)`
`3 * ( x + 2 ) = 15`
`=> x + 2 = 15 \div 3`
`=> x + 2 = 5`
`=> x = 5 - 2`
`=> x = 3`
Vậy, `x = 3`
`d)`
`10 * x + 15 * 11 = 20 * 10`
`=> 10x + 165 = 200`
`=> 10x = 200 - 165`
`=> 10x = 35`
`=> x = 35 \div 10`
`=> x = 3,5`
Vậy,` x = 3,5`
`e)`
`4 * ( x + 2 ) = 3 * 4`
`=> x + 2 = 12 \div 4`
`=> x + 2 = 3`
`=> x = 3 - 2`
`=> x = 1`
Vậy,` x = 1`
`f)`
`33 x + 135 = 26 * 9`
`=> 33x + 135 = 234`
`=> 33x = 234 - 135`
`=> 33x = 99`
`=> x = 99 \div 33`
`=> x = 3`
Vậy, `x = 3`
`g)`
`2 * x + 15 + 16 + 17 = 100`
`=> 2x + 48 = 100`
`=> 2x = 100 - 48`
`=> 2x = 52`
`=> x = 52 \div 2`
`=> x =26`
`h)`
`2 * (x + 9 + 10 + 11) = 4 . 12 . 25`
`=> 2 * (x + 9 + 10 + 11) = 4*25*12`
`=> 2 * (x + 9 + 10 + 11) = 100*12`
`=> x + 9 + 10 + 11 = 100*12 \div 2`
`=> x + 30 = 600`
`=> x = 600 - 30`
`=> x = 570`
Vậy, `x = 570.`
a) \(x+10=20\Leftrightarrow x=10\)
b) \(2x+15=35\Leftrightarrow2x=20\Leftrightarrow x=10\)
c) \(3.\left(x+2\right)=15\Leftrightarrow x+2=5\Leftrightarrow x=3\)
d) \(10x+15.11=20.10\Leftrightarrow10x+165=200\Leftrightarrow10x=35\Leftrightarrow x=\dfrac{35}{10}=\dfrac{7}{2}\)
e) \(4.\left(x+2\right)=3.4\Leftrightarrow x+2=3\Leftrightarrow x=1\)
f) \(35x+135=26.9\Leftrightarrow35x=234-135\Leftrightarrow35x=99\Leftrightarrow x=\dfrac{99}{35}\)
g) \(2x+15+16+17=100\Leftrightarrow2x+48=100\Leftrightarrow2x=52\Leftrightarrow x=26\)
h) \(2.\left(x+9+10+11\right)=4.12.25\)
\(\Leftrightarrow x+30=2.12.25\)
\(\Leftrightarrow x=600-30\)
\(\Leftrightarrow x=570\)
Áp dụng bất đẳng thức AM - GM:
\(\sqrt{\left(x^2-15\right)\left(x-3\right)}\le\dfrac{x^2-15+x-3}{2}=\dfrac{x^2+x-18}{2};\sqrt{x^2-15}\le\dfrac{x^2-15+1}{2}=\dfrac{x^2-14}{2};\sqrt{x-3}\le\dfrac{x-3+1}{2}=\dfrac{x-2}{2}\).
Do đó \(F\ge x^2+x-\dfrac{x^2+x-18}{2}-\dfrac{x^2-14}{2}-\dfrac{x-2}{2}-38=-21\).
Đẳng thức xảy ra khi x = 4.
Vậy...
\(-4+x=-4+7\)
\(\Rightarrow x=-4+7+4\)
\(\Rightarrow x=7\)
\(\left(-3\right)-\left(-5-x\right)=-15+\left(-6+15\right)\)
\(\Rightarrow x=-15-6+15+3-5\)
\(\Rightarrow x=-8\)
\(-\left(x+2\right)+2=\left(8-15\right)+15\)
\(\Rightarrow-x+2+2=-7+15\)
\(\Rightarrow-x=-7+15-2-2\)
\(\Rightarrow x=-4\)
\(4+\left(x-4\right)=-\left(11-2\right)+\left(11+4\right)\)
\(\Rightarrow4+x-4=-11+2+11+4\)
\(\Rightarrow x=-11+2+11+4-4+4\)
\(\Rightarrow x=6\)
a) -4 + x = -4 + 7 b) (-3) - (-5-x) = -15 + (-6+15)
-4 + x + 4 - 7 = 0 (-3) + 5 + x = -6
x - 7 = 0 2 + 6 = -x
x= 7 8 = -x
Vậy x= 7 x= -8 =) Vậy x= -8
c) -(x+2)+2=(8-15)+15 d) 4+(x-4)= -(11-2) + (11+4 )
-x - 2 + 2 = 8 4+x-4 = 6
-x = 8 x=6
x= -8 Vậy x=6
Vậy x= -8
\(=\dfrac{4}{15}x\left(13+4-2\right)=\dfrac{4x15}{15}=4\)
hộ mik nha
a)\(2.x-\frac{3}{2}=\frac{1}{2}\)
\(2x=\frac{4}{2}\)
\(x=\frac{4}{2}:2\)
\(x=1\)
Vậy x=1
b)\(\frac{8}{13}.x+\frac{5}{13}.x=\frac{1}{10}\)
\(x.\left(\frac{8}{13}+\frac{5}{13}\right)=\frac{1}{10}\)\
\(x.1=\frac{1}{10}\)
\(x=\frac{1}{10}\)
Vậy x=\(\frac{1}{10}\)
c)\(\frac{2}{15}+\frac{7}{15}.x=\frac{1}{15}\)
\(\frac{7}{15}x=\frac{-1}{15}\)
x=\(\frac{-1}{7}\)
Vậy \(x=\frac{-1}{7}\)
\(\frac{3}{2}\cdot x-\frac{3}{2}=\frac{1}{2}\) \(\frac{8}{13}\cdot x+\frac{5}{13}\cdot x=\frac{1}{10}\)
\(\frac{3}{2}\cdot x=\frac{3}{2}+\frac{1}{2}=2\) \(\left[\frac{8}{13}+\frac{5}{13}\right]\cdot x=\frac{1}{10}\)
\(x=2:\frac{3}{2}\) \(1\cdot x=\frac{1}{10}\)
x=\(\frac{4}{3}\) \(x=\frac{1}{10}:1\)
Vậy x=\(\frac{4}{3}\) \(x=\frac{1}{10}\)
Vậy x=\(\frac{1}{10}\)
c,\(\frac{2}{5}+\frac{7}{15}\cdot x=\frac{1}{15}\)
\(\frac{7}{15}\cdot x=\frac{1}{15}-\frac{2}{5}=\frac{-1}{3}\)
\(x=\frac{-1}{3}:\frac{7}{15}\)
\(x=\frac{-5}{7}\)
Vậy x=\(\frac{-5}{7}\)
a) x + 10 = 20
<=> x = 20 - 10 = 10
Vậy x = 10
b) 2x + 15 = 35
<=> 2x = 35 - 15 = 20
<=> x = 10
Vậy x = 10
c) 3(x + 2) = 15
<=> x + 2 = 15 : 3 = 5
<=> x = 5 - 2 = 3
Vậy x = 3
d) 10x + 15.11 = 20.10
<=> 10x + 165 = 200
<=> 10x = 200 - 165 = 35
<=> x = 35 : 10 = 3,5
Vậy x = 3,5
e) 4(x + 2) = 3.4
<=> x + 2 = 3
<=> x = 3 - 2 = 1
Vậy x = 1
f) 33x + 135 = 26.9
<=> 33x + 135 = 234
<=> 33x = 234 - 135 = 99
<=> x = 99 : 33 = 3
Vậy x = 3
g) 2x + 15 + 16 + 17 = 100
<=> 2x + 48 = 100
<=> 2x = 100 - 48 = 52
<=> x = 52 : 2 = 26
Vậy x = 26
h) 2(x + 9 + 10 + 11) = 4.12.5
<=> x + 30 = 120
<=> x = 120 - 30 = 90
Vậy x = 90
15×2=30
Tik mik nha
15 x 2 = 30 . Tick mk nha Nguyễn Thị Hạnh !!!