d.0-(-275)-(-127)-(-34)
e.[25*(30-51)-20*(-17)]:(-5)
g.(-300*87+(-105)*7)-15
Giúpmik nha cần rất gấp
bài 19: tìm x
a) 5 . ( x - 7 ) = 0
b) 25 ( x - 4 ) = 0
c) ( 34 - 2x ) . ( 2x - 6 ) = 0
d) ( 2019 - x ) . ( 3x - 12 ) 0
e) 57 . ( 9x - 27 ) = 0
f) 25 + ( 15 - x ) = 30
g) 43 - ( 24 - x ) = 20
h) 2 . ( x - 5 ) - 17 = 25
i) 3 . ( x + 7 ) - 15 = 27
j) 15 + 4 . ( x - 2 ) = 95
k) 20 - ( x + 14 ) = 5
l) 14 + 3 . ( 5 - x ) = 27
a) \(5\left(x-7\right)=0\)
\(\Rightarrow x-7=0\)
\(\Rightarrow x=7\)
b) \(25\left(x-4\right)=0\)
\(\Rightarrow x-4=0\)
\(\Rightarrow x=4\)
c) \(\left(34-2x\right)\left(2x-6\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}34-2x=0\\2x-6=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x=34\\2x=6\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=17\\x=3\end{matrix}\right.\)
d) \(\left(2019-x\right)\left(3x-12\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}2019-x=0\\3x-12=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2019\\3x=12\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2019\\x=\dfrac{12}{3}=4\end{matrix}\right.\)
e) \(57\left(9x-27\right)=0\)
\(\Rightarrow9x-27=0\)
\(\Rightarrow9\left(x-3\right)=0\)
\(\Rightarrow x-3=0\)
\(\Rightarrow x=3\)
a) 5.(x-7)=0⇔x-7=0⇔x=7
b) 25(x-4)=0⇔x-4=0⇔x=4
c) (34-2x).(2x-6)=0
⇔ 34-2x=0 hoặc 2x-6=0
⇔2x=34 hoặc 2x=6
⇔ x=17 hoặc x=3
d) (2019-x).(3x-12)=0
⇔ 2019-x=0 hoặc 3x-12=0
⇔ x=2019 hoặc x=4
e) 57.(9x-27)=0
⇔ 9x-27=0
⇔ x=3
f) 25+(15-x)=30
⇔ 15-x=5
⇔ x=10
g) 43-(24-x)=20
⇔ 24-x=23
⇔ x=1
h) 2.(x-5)-17=25
⇔ 2(x-5)=42
⇔x-5=21
⇔ x=26
i) 3(x+7)-15=27
⇔ 3(x+7)=42
⇔ x+7=14
⇔ x=7
j) 15+4(x-2)=95
⇔ 4(x-2)=80
⇔ x-2=20
⇔ x=22
k) 20-(x+14)=5
⇔ x+14=15
⇔ x=1
l) 14+3(5-x)=27
⇔ 3(5-x)=13
⇔ 5-x=13/3
⇔ x=5-13/3
⇔ x=2/3
1.Tính hợp lí:
a, [ 13-17 ].[-10]+[-7]0
b, 72.[28-49] + 28.[-49-72]
c, -65.[87-17] - 87.[17-65]
d, -23.63+23.21-58.23
e, 25.134+25.[-34]
Giúp mình với mình đang cần gấp!
a, [ 13-17 ].[-10]+[-7]0
=-4.[-10]+1
=40+1
=41
b, 72.[28-49] + 28.[-49-72]
=72.[-21]+28.[-121]
=-1512+[-3388]
=-4900
c, -65.[87-17] - 87.[17-65]
=-65.70-87.[-48]
=4550-[-4276]
=8726
d, -23.63+23.21-58.23
=23.(-63)+23.21-58.23
=23.(-63+23-58)
=23.(-40-58)
=23.(-98)
=-2254
e, 25.134+25.[-34]
=25.[134+(-34)]
=25.100
=2500
bài 19: tìm x
c) ( 34 - 2x ) . ( 2x - 6 ) = 0
d) ( 2019 - x ) . ( 3x - 12 ) 0
e) 57 . ( 9x - 27 ) = 0
f) 25 + ( 15 - x ) = 30
g) 43 - ( 24 - x ) = 20
h) 2 . ( x - 5 ) - 17 = 25
i) 3 . ( x + 7 ) - 15 = 27
j) 15 + 4 . ( x - 2 ) = 95
k) 20 - ( x + 14 ) = 5
l) 14 + 3 . ( 5 - x ) = 27
nhanh nha, mik tick cho, ccau trình bày dễ hiểu, ko cần ''hoặc''
`@` `\text {Ans}`
`\downarrow`
`c)`
`( 34 - 2x ) . ( 2x - 6 ) = 0`
`=>`\(\left[{}\begin{matrix}34-2x=0\\2x-6=0\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}2x=34\\2x=6\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=34\div2\\x=6\div2\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=17\\x=3\end{matrix}\right.\)
Vậy, `x \in {17; 3}`
`d)`
`( 2019 - x ) . ( 3x - 12 ) =0` `?`
`=>`\(\left[{}\begin{matrix}2019-x=0\\3x-12=0\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=2019-0\\3x=12\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=2019\\x=12\div3\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=2019\\x=4\end{matrix}\right.\)
Vậy, `x \in {2019; 4}`
`e) `
`57 . ( 9x - 27 ) = 0`
`=>`\(9x-27=0\div57\)
`=> 9x - 27 = 0`
`=> 9x = 27`
`=> x = 27 \div 9`
`=> x = 3`
Vậy, `x = 3`
`f)`
`25 + ( 15 - x ) = 30`
`=> 15 - x = 30 - 25`
`=> 15 - x = 5`
`=> x = 15 -5 `
`=> x = 10`
Vậy, `x = 10`
`g) `
`43 - ( 24 - x ) = 20`
`=> 24 - x = 43 - 20`
`=> 24 - x = 23`
`=> x = 24 - 23`
`=> x = 1`
Vậy, `x = 1`
`h) `
`2 . ( x - 5 ) - 17 = 25`
`=> 2 ( x - 5) = 25+17`
`=> 2 ( x - 5) = 42`
`=> x - 5 = 42 \div 2`
`=> x - 5 = 21`
`=> x = 21 + 5`
`=> x = 26`
Vậy, `x = 26`
`i)`
`3 . ( x + 7 ) - 15 = 27`
`=> 3(x + 7) = 27 + 15`
`=> 3(x + 7) = 42`
`=> x +7 = 42 \div 3`
`=> x + 7 = 14`
`=> x = 14 - 7`
`=> x = 7`
Vậy, `x = 7`
`j)`
`15 + 4 . ( x - 2 ) = 95`
`=> 4(x - 2) = 95 - 15`
`=> 4(x - 2) = 80`
`=> x - 2 = 80 \div 4`
`=> x - 2 = 20`
`=> x = 20 + 2`
`=> x = 22`
Vậy, `x = 22`
`k)`
`20 - ( x + 14 ) = 5`
`=> x + 14 = 20 - 5`
`=> x + 14 = 15`
`=> x = 15 - 14`
`=> x = 1`
Vậy, `x = 1`
`l) `
`14 + 3 . ( 5 - x ) = 27`
`=> 3(5 - x) = 27 - 14`
`=> 3(5 - x) = 13`
`=> 5 - x = 13 \div 3`
`=> 5 - x = 13/3`
`=> x = 5- 13/3`
`=> x = 2/3`
Vậy, `x = 2/3.`
`@` `\text {Kaizuu lv uuu}`
1.thực hiện phép tính bằng cách hợp lí
a.(-46)+(-125)+46+25 b.25.(-15)+25.(-5)+(-20).75
c.(-151)+(-37)+(-42)+(-63)+142 d.32+(-149)+(-311)+(-89)+(-51)
e.-65.(87-17)-87.(17-65) g.-43.(53-16) - 53.(16-43)
2.tím x thuộc z biết
a.(-5)^2-(5x-3)=4 d.3x^2=12
b.5x-15=-75-x e.|2x-3|=7
c.-2x-40=(5-x)-(-15+60) g. 19-(43-|x|)=45
h.|x-1|+(-5)=2 i.-10-|5-x|=-12
f.32-8.|2x-9|=24 k.4.|x-5|-54=-34 l.259-51.|4x+3|=(-10)^2.3+10^1
3.tìm các số nguyên x,y biết
a.xy+3x-y-5=0
b.xy-2x+y-3=0
1. Thực hiện phép tính bằng cách hợp lí :
a) (-46) + (-125) + 46 + 25 = [(-46)+46] + [(-125)+25]
= 0+(-100) = -100
b) 25.(-15) + 25.(-5) + (-20).75 = 25.[(-15)+(-5)] + (-20).75
= 25.(-20) + (-20).75 = (-20).(25+75) = (-20).100 = -2000
c) (-151)+(-37)+(-42)+(-63)+142 =(-151)+[(-37)+(-63)]+[(-42)+142]
= (-151) + [(-100) + 100] = -151
d)32+(-149)+(-311)+(-89)+(-51) = 32+[(-149)+(-51)] + [(-311)+(-89)]
= 32+[(-200)+(-400)] = 32+(-600) = -568
e)-65.(87-17)-87.(17-65) = (-65).87 - (-65).17 - 87.17 + 87.65
= (-65).87 + 65.17 - 87.17 + 87.65 = [(-65).87+87.65] + 65.(17-87)
= 65.(-70) = -4550
g) -43.(53-16) - 53.(16-43) = (-43).53 - (-43).16 - 53.16 + 53.43
= (-43).53 + 43.16 - 53.16 + 53.43 = [(-43).53+53.43] + 16.(43-53)
= 16.(-10) = -160
Thực hiện phép tính
a) 17+25 . 4- 3^3
b) 12 . 5^3 - 162 : 3^2
c) 2347 - [ 75 - ( 9 - 4 )^2 ]
d) 1672 + [49 + ( 13 - 7 )^3 ]
e) 250 : { 5.(1997 - 1869 ) - 78 ] }
g) ( 173948 - 35 ) : 87 + 97 . 11
h) 1246 + 12 . 95 : 20 - 303
i) 100 -[ ( 64 - 48 ) . 5 + 88 ] : 28
j) 667 - 195 . 93 : 465 + 372
k) ( 2032 + 73 . 254 ) : 127 -61
Giúp mk với , mk đag cần gấp , cám ơn
a) 15 x 21 - 16 : 4 + 7
b) 123 - 11 x 6 + 150 : 30
c) 2017 + 5 x [300- (715 - 15): 7
d)1560 : [5 x 79 - (125 + 5 x 49) + 5 x 21]
d) 50 - [ (20 - 8) : 2 + 34]
e) 10 - [ (64 - 48) x 5 + (8 x 10 + 8) ] : 28
CÁC BẠN LÀM MÌNH 1 CÂU CŨNG ĐƯỢC TỐI NAY MÌNH ĐANG CẦN GẤP NHA!!!!
a) 15 x 21 - 16 : 4 + 7
= 315 - 4 + 7
= 311 + 7
= 318
b) 123 - 11 x 6 + 150 : 30
= 123 - 66 + 5
= 57 + 5
= 62
Mình chỉ làm đến đó thôi chứ mấy câu còn lại khó hiểu quá!Ở lớp 5 mình chưa học bao giờ.
a)
=315-4+7=318
b)
=123-66+5=62
c)
=2017+5x[300-700:7]
=2017+5x[300-100]
=2017+5x200
=2017+1000
=3017
d)
=1560:[5x79-370+5x21]
=1560:[395-370+105]
=1560:130
=12
e)
=50-[12:2+34]
=50-40
=10
g)
=10-[16x5+88]:28
=10-168:28
=10-6
=4
a) 15x21 -16:4 +7
= 315-4 +7
=311+7
=318
b) 123 -11x6+150:30
=123-66+5
=57+5
=62
c)2017+5x[300-(715-15):7
=2017+5x[300-(700:7)
=2017+5x[300-100]
=2017+5x200
=2017+1000
=3017
Tìm các số nguyên x, biết :
a, -65 - (x+15) + 105 = 0
b, |-6| + (-9) - (x+1) = 7
c, |5-x| + (-25 + 7) = -3 - (-10)
d, 28 - |x+6| + (-2) = 0
e, x - (13 - 15) = 5 + (10 - x) - (-1)
f, -120 - (x - 5) = 125
g, 10 - (-5 + 2) + (-9) = (-20 + 7) - x
Mình cần gấp ngay tối nay ( ghi đầy đủ các bước )
a) \(-65-\left(x+15\right)+105=0\)
\(-65-\left(x+15\right)=-105\)
\(x+15=-65-\left(-105\right)\)
\(x+15=40\)
\(x=25\)
b) |-6| + (-9) - (x+1) = 7
-3- (x+1) =7
x+1 = -10
x = -11
c)\(\left|5-x\right|+\left(-25+7\right)=-3-\left(-10\right)\)
\(\left|5-x\right|+\left(-18\right)=7\)
\(\left|5-x\right|=25\)
\(\Rightarrow\orbr{\begin{cases}5-x=25\\5-x=-25\end{cases}\Rightarrow\orbr{\begin{cases}x=-20\\x=30\end{cases}}}\)
d) \(28-\left|x+6\right|+\left(-2\right)=0\)
\(28-\left|x+6\right|=2\)
\(\left|x+6\right|=26\)
\(\Rightarrow\orbr{\begin{cases}x+6=26\\x+6=-26\end{cases}\Rightarrow\orbr{\begin{cases}x=20\\x=-32\end{cases}}}\)
e) \(x-\left(13-15\right)=5+\left(10-x\right)-\left(-1\right)\)
\(x+2=5+10-x+1\)
\(x+2=16-x\)
\(x+x=16-2\)
\(2x=14\)
\(x=7\)
f) \(-120-\left(x-5\right)=125\)
\(x-5=-120-125\)
\(x-5=-245\)
\(x=-240\)
g) \(10-\left(-5+2\right)+\left(-9\right)=\left(-20+7\right)-x\)
\(-16=-13-x\)
\(x=-13+16\)
\(x=3\)
Tính
a) 125 - ( -314 ) c) ( -127 ) - ( -34 )
b) 0 - ( -275 ) d) 152 - 317
cần gấp
a) 125 - (-314)
= 125 + 314
= 439
b) 0 - (-275)
= 0 + 275
= 275
c) (-127) - (-34)
= -127 + 34
= -93
d) 152 - 317 = -165
a,440
b,275
c,-93
d,-165
h mình nha! cảm ơn nhiều
a) = 439
b) = 275
c) = 93
d) = 165 nha bạn!
chúc bạn học giỏi!
Tìm x biết:
a) 5.(x-7) = 0
b) 34.(2.x - 6 ) = 0
c) 25 + (15-x) = 30
d) 43 -(24-x) = 20
e) 2. (x - 5) -17 =25
f) 24 + 3.(5 - x) = 27
g) 15 : x – 2 = 3
h) (32 – x : 5): 13 = 2
g) (6 – 2x)(x – 8) =0
Mg bt câu nào thỳ giúp mk câu đó nhé
a ) \(5.\left(x-7\right)=0\)
\(\Leftrightarrow x-7=5.0\)
\(\Leftrightarrow x-7=0\)
\(\Leftrightarrow x=7\)
b ) \(34.\left(2.x-6\right)=0\)
\(\Leftrightarrow2.x-6=34.0\)
\(\Leftrightarrow2.x-6=0\)
\(\Leftrightarrow2.x=0+6\)
\(\Leftrightarrow2.x=6\)
\(\Leftrightarrow x=6\div2\)
\(\Leftrightarrow x=3\)
c ) \(25+\left(15-x\right)=30\)
\(\Leftrightarrow25+\left(15-x\right)=-\left(x-40\right)\)
\(\Leftrightarrow-\left(x-40\right)=2.3.5\)
\(\Leftrightarrow40-x=30\)
\(\Leftrightarrow-x=-10\)
\(\Leftrightarrow x=10\)
d ) \(43-\left(24-x\right)=20\)
\(\Leftrightarrow24-x=43-20\)
\(\Leftrightarrow24-x=23\)
\(\Leftrightarrow x=24-23\)
\(\Leftrightarrow x=1\)
e ) \(2.\left(x-5\right)-17=25\)
\(\Leftrightarrow2.\left(x-5\right)=25+17\)
\(\Leftrightarrow2.\left(x-5\right)=42\)
\(\Leftrightarrow x-5=42\div2\)
\(\Leftrightarrow x-5=21\)
\(\Leftrightarrow x=21+5\)
\(\Leftrightarrow x=26\)
f ) \(24+3.\left(5-x\right)=27\)
\(\Leftrightarrow3.\left(5-x\right)=27-24\)'
\(\Leftrightarrow3.\left(5-x\right)=3\)
\(\Leftrightarrow5-x=3\div3\)
\(\Leftrightarrow5-x=1\)
\(\Leftrightarrow x=5-1\)
\(\Leftrightarrow x=4\)
g ) \(15\div x-2=3\)
\(\Leftrightarrow15\div x=3+2\)
\(\Leftrightarrow15\div x=5\)
\(\Leftrightarrow x=15\div5\)
\(\Leftrightarrow x=3\)
h ) \(\left(32-x\div5\right)\div13=2\)
\(\Leftrightarrow32-x\div5=2\times13\)
\(\Leftrightarrow32-x\div5=26\)
\(\Leftrightarrow x\div5=32-26\)
\(\Leftrightarrow x\div5=6\)
\(\Leftrightarrow x=5.6\)
\(\Leftrightarrow x=30\)
g ) \(\left(6-2x\right)\left(x-8\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}6-2x=0\\x-8=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=8\end{matrix}\right.\)
Vậy \(x\in\left\{3;8\right\}\)
Mình làm hết nhaa !!
a)5.(x-7)=0
x-7=0:5
x-7=0
x=0+7
x=7
Vậy x=7
b)34.(2x-6)=0
2x-6 =0:34
2x-6 =0
2x=0+6
2x=6
x=6:2
x=3
Vậy x= 3
c)25+(15-x)=30
15-x=30-25
15-x=5
x=15-5
x=10
Vậy x=10
d)43-(24-x)=20
24-x =43-20
24-x=23
x=24-23
x=1
vậy x=1
e)2(x-5)-17=25
2(x-5)=25+17
2(x-5)=42
x-5=42:2
x-5=21
x=21+5
x=26
Vậy x=26
f)24+3(5-x)=27
3(5-x)=27-24
3(5-x)=3
5-x =3:3
5-x=1
x=5-1
x=4
Vậy x=4
g)15:x-2=3
15:x=3+2
15:x=5
x=15:5
x=3
Vậy x=3
h)( 32-x:5):13=2
32-x:5 =2.13
32-x :5=26
x:5= 32-26
x:5=6
x=6.5
x=30
Vậy x=30
k)(6-2x)(x-8)=0
➩6-2x=0 hoặc x-8=0
2x=6-0 x=0+8
2x=6 x=8
x=6:2
x=3
Vậy x=3 hoặc x=8