a:35-x=25-(-13) b:27+(35-27)=(x+758)-758
c:x(39+x)=2x-27 d:2x-1257=(16-25)-1257
cần gấp
Bài 1 : Tìm số nguyên x , biết
a, 27 + ( 35 - 27 ) = (x+758)-758
b, x - ( 39 + x) = 2x - 37
c, 2x -1257 = (_16 - 25 ) - 1257
Giải giúp mk ạ ! Mk hứa sẽ tick hết cho
Bài 2: Tính nhanh:
a)184 x 72 + 184 x 27 + 184
c)1999 x 346 + 1999 + 653 x 1999
e)23 x 5 x 7 x 4
b)1996 x 1257 – 1996 – 256 x 1996
d)24 x 89 + 24 + 16 x 15
g)25 x 36 x 13
a)184 x 72 + 184 x 27 + 184
=184 x 72 + 184 x 27 + 184 x 1
= 184 x (72 + 27 + 1 )
=184 x 100=18400
c)1999 x 346 + 1999 + 653 x 1999
=1999 x 346 + 1999 + 653 x 1999 x 1
= 1999 x ( 346 + 653 + 1 )
= 1999 x 1000=1999000
e)23 x 5 x 7 x 4
= ( 23 x 7) x( 5 x 4)
= 161 x 20= 3220
b)1996 x 1257 – 1996 – 256 x 1996
=1996 x 1257 – 1996 – 256 x 1996 x 1
= 1996 x ( 1257 - 256 - 1 )
= 1996 x 1000= 1996000
a ) 184 x 72 +184 x 27 + 184
= 184 x ( 72 + 27 ) + 184
= 184 x 99 + 184
= 18216 + 184
= 18400
c) 1999 x 346 + 1999 + 653 x 1999
= 1999 x ( 346 + 653 ) + 1999
= 1999 x 999 + 1999
= 1997001 + 1999
= 1999000
e) 23 x 5 x 7 x 4
= 23 x 7 x 5 x 4
= 161 x 20
= 3220
b) 1996 x 1257 -1996 - 256 x 1996
= 1996 x ( 1257 - 256 ) - 1996
= 1996 x 1001 - 1996
= 1997996 - 1996
= 1996000
d) 24 x 89 + 24 + 16 x 15
= 24 x 89 + 16 x 15 + 24
= 2136 + 240 + 24
= 2400
g) 25 x 36 x 13
= 25 x 36 x 13
= 900 x 13
= 11700
bài này làm hơi lâu nhưng khá dễ lần sau bạn nên tự
làm nha ♥♥
Thực hiện phép tính :
a) 123 - 27 + 27 + 13 - 123
b) 175 + 25 + 13 + 15 - 175 - 25
c) 53 x 39 + 47 x 39 + 53 x 21 + 47 x 21
d) 49 x 35 + 49 x 16 - 49 x 61
a) `123 - 27 + 27 + 13 - 123`
`= (123 - 123) + (27 - 27) + 13`
`= 0 + 0 + 13`
`= 13`
`---`
b) `175 + 25 + 13 + 15 - 175 - 25`
`= (175-175)+(25-25)+25+13`
`=0+0+25+13`
`=28`
`---`
c) \(53\times39+47\times39+53\times21+47\times21\)
\(=\text{[}\left(53+47\right)\times39]+\left[\left(53+47\right)\times21\right]\)
\(=\left(100\times39\right)+\left(100\times21\right)\)
\(=3900+2100\)
`=6000`
`---`
d) \(49\times35+49\times16-49\times61\)
`=` \(49\times\left(35+16-61\right)\)
`=` \(49\times\left(-10\right)\)
`=-490`
Tính
a) 27 - ( -15 ) - 2
b) ( -12 ) + 35 - 8
c) x + 37 + ( -17 ) + 25
d) ( -66 ) - ( y - 16 ) + 150
cần gấp
a) 27-(-15)-2 =27+15-2
=40
b)(-12)+35-8=23-8
= 15
c)x + 37 + ( -17 ) + 25=x +20+25
=x+45
d) ( -66 ) - ( y - 16 ) + 150=66-y+16 +150
=66-y+166
=66+166-y
= 232+y
k mình nha!Chúc bạn học tốt!!!!^-^
a,27-(-15)-2
=42-2
=40
b,(-12)+35-8
=23-8
=15
c,x+37+(-17)+25
=x+[37+(-17)+25]
=x+45
d,(-66)-(y-16)+150
=(-66)-y+16+150
=-y+[(-66)+16+150]
=-y+100
=100+(-y)
=100-y
a) 40
b) 15
c) x + 45
d) 100 - y
1/ 3(x - 1) - 5(x - 2) = 4(x + 1)
2/ -2(x - 2) - 4(x + 1) = -3(x + 3)
3/ 3x\(^2\) + 2x = 0
4/ x\(^2\) - 5x = 0
5/ (2x - 3)\(^2\) = 36
6/ (5x - 1)\(^3\) = 125
7/ 3\(^x\) + 1 = 27
1) Ta có: \(3\left(x-1\right)-5\left(x-2\right)=4\left(x+1\right)\)
\(\Leftrightarrow3x-5-5x+10-4x-4=0\)
\(\Leftrightarrow-6x+1=0\)
\(\Leftrightarrow-6x=-1\)
hay \(x=\dfrac{1}{6}\)
2) Ta có: \(-2\left(x-2\right)-4\left(x+1\right)=-3\left(x+3\right)\)
\(\Leftrightarrow-2x+4-4x-4+3x+9=0\)
\(\Leftrightarrow-3x=-9\)
hay x=3
3) Ta có: \(3x^2+2x=0\)
\(\Leftrightarrow x\left(3x+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{2}{3}\end{matrix}\right.\)
4) Ta có: \(x^2-5x=0\)
\(\Leftrightarrow x\left(x-5\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=5\end{matrix}\right.\)
5) Ta có: \(\left(2x-3\right)^2=36\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-3=6\\2x-3=-6\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=9\\2x=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{9}{2}\\x=-\dfrac{3}{2}\end{matrix}\right.\)
6) Ta có: \(\left(5x-1\right)^3=125\)
\(\Leftrightarrow5x-1=5\)
\(\Leftrightarrow5x=6\)
hay \(x=\dfrac{6}{5}\)
7) Ta có: \(3^{x+1}=27\)
\(\Leftrightarrow x+1=3\)
hay x=2
Tính hợp lí nhất
1. 2155- (174 + 2155) + (-68 + 174)
2. -25 * 72 + 25 * 21 - 49 * 25
3. 35* (14-23) - 23 * (14-35)
4. 8154 - (674 + 8154) + (-98 + 674)
5. -25 * 21 + 25 * 72 + 49 * 25
6. 27* (13 - 16) - 16* (13 - 27)
7.-1911 - ( 1234 - 1911)
8.156 * 72 + 28 *156
9. 32 * (-39) + 16 * (-22)
10. -1945 - ( 567 - 1945 )
11. 184 * 33 + 67 * 184
12. 44 * ( -36 ) + 22 * ( -28)
Mọi người giúp em với
1: Ta có: \(2155-\left(174+2155\right)+\left(-68+174\right)\)
\(=2155-174-2155-68+174\)
=-68
2) Ta có: \(-25\cdot72+25\cdot21-49\cdot25\)
\(=-25\cdot\left(72-21+49\right)\)
\(=-25\cdot100=-2500\)
Tìm số nguyên x biết:
a) 22 + (2x - 13) = 83;
b) 51 - ( -12 + 3x) = 27;
c) - (2x + 2) + 21 = - 23;
d) 25 - ( 25 - x) = 0.
a) 22 + (2x -13) = 83 => 2x -13 = 61 => x = 37.
b) 51 - (-12 + 3x) = 27 => 63 - 3x = 27 => x = 12.
c) - (2x + 2) + 21 = - 23 => 2x + 2 = 44 => x = 21.
d) 25 - (25 - x) = 0 => 25 - 25 + x = 0 => x = 0.
Tìm số nguyên x biết: a) 22 + (2x - 13) = 83; b) 51 - ( -12 + 3x) = 27 c) - (2x + 2) + 21 = - 23; d) 25 - ( 25 - x) = 0
tìm số nguyên x biết a)x+(-5)=10 b)-2x-(-27)=25 mình cần gấp
a)\(x+\left(-5\right)=10\)
⇔\(x-5=10\)
⇔\(x=15\)
b)\(-2x-\left(-27\right)=25\)
⇔\(-2x+27=25\)
⇔\(-2x=-2\)
⇔\(x=1\)