1560 : [5 x 79-(125+5x 49 ) + 5 x 21]
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
Thực hiện phép tính theo cách hợp lí:
a) 59 . 73 - 302 +27 . 59
b) 1560 : [5 . 79 -( 125 + 5. 49) + 5. 21]
bạn nào có lời giải chi tiết tớ sẽ tick
a) 59 . 73 - 302 +27 . 59
=59x(73+27)-302
=59x100-302
=5900-900
=5000
b) 1560 : [5 . 79 -( 125 + 5. 49) + 5. 21]
=1560:[5.79-(125+245)+5.21)
=1560:[5.(79+21)-(125+245)
=1560:[500-370]
=1560:130
=12
a.\(\dfrac{5x+2}{6}-\dfrac{8x-1}{3}=\dfrac{4x+2}{5}-5\)
b.\(x-\dfrac{2x-5}{5}+\dfrac{x+8}{6}=7+\dfrac{x-1}{3}\)
c.\(\dfrac{x+1}{15}+\dfrac{x+2}{7}+\dfrac{x+4}{4}+6=0\)
d.\(\dfrac{x-342}{15}+\dfrac{x-323}{17}+\dfrac{x-300}{19}+\dfrac{x-273}{21}=10\)
e.\(\dfrac{x+97}{125}+\dfrac{x-63}{35}=\dfrac{x-7}{21}+\dfrac{x-77}{49}\)
a. \(\dfrac{5x+2}{6}-\dfrac{8x-1}{3}=\dfrac{4x+2}{5}-5\)
<=> \(5\left(5x+2\right)-10\left(8x-1\right)=6\left(4x+2\right)-6\cdot5\)
<=> \(25x+10-80x+10=24x+12-30\)
<=> \(25x-80x-24x=12-30-10-10\)
<=> \(-79x=-38\)
<=> \(x=\dfrac{-38}{-79}\)
\(x=\dfrac{38}{79}\)
b. \(x-\dfrac{2x-5}{5}+\dfrac{x+8}{6}=7+\dfrac{x-1}{3}\)
<=> \(30\cdot x-6\left(2x-5\right)+5\left(x+8\right)=30\cdot7+10\left(x-1\right)\)
<=> \(30x-12x+30+5x+40=210+10x-10\)
<=> \(30x-12x+5x-10x=210-10-30-40\)
<=> \(13x=130\)
<=> \(x=\dfrac{130}{13}\)
\(x=10\)
c. \(\dfrac{x+1}{15}+\dfrac{x+2}{7}+\dfrac{x+4}{4}+6=0\)
<=> \(28\left(x+1\right)+60\left(x+2\right)+105\left(x+4\right)+420\cdot6=0\)
<=> \(28x+28+60x+120+105x+420+2520=0\)
<=> \(28x+60x+105x=-28-120-420-2520\)
<=> \(193x=-3088\)
<=> \(x=\dfrac{-3088}{193}\)
\(x=-16\)
d. \(\dfrac{x-342}{15}+\dfrac{x-323}{17}+\dfrac{x-300}{19}+\dfrac{x-273}{21}=10\)
<=> \(6783\left(x-342\right)+5985\left(x-323\right)+5355\left(x-300\right)+4845\left(x-273\right)=101745\cdot10\)
<=> \(6783x-2319786+5985x-1933155+5355x-1606500+4845x-1322685=1017450\)
<=> \(6783x+5985x+5355x+4845x=1017450+2319786+1933155+1606500+1322685\)
<=> \(22968x=8199576\)
<=> \(x=\dfrac{8199576}{22968}\)
\(x=357\)
Tìm x thuộc Z, biết: 1. 2 |x - 1| - 5(x + 3) - 2(x-7) = |x - 1|- 7x 2. |x - 2| - 5(x - 4) =20 - 5x 3. 4(x - 2) - 3(x + 4 =(-4)(+3)(-125)(+25)(-8) 4. -3(2x - 4) + 7(x-5) = (-67)(1-301) - 301 . 67 5. 7(x - 5) - 4(x+3) = 2(x - 5)+ (13-135 + 49 ) - (13+49) 6. 5(x-3) - 2(x + 1)= 3 + 2(x-1)+(18 + 29) +( 185 - 18 - 29)
Bài 1
79-(4x-13)=75
441:21+(125-3x)=24
5x+(3x-11)=69
5(x-1)+4x=4
Bài 2
Viết dạng tổng quát của các số chia hết cho 4, chia hết cho 4 dư 1, chia hết cho 4 dư 2, chia hết cho 4 dư 3
Bài 1 :
\(79-\left(4x-13\right)=75\)
\(4x-13=4\)
\(4x=17\)
\(x=\frac{17}{4}\)
\(441:21+\left(125-3x\right)=24\)
\(21+\left(125-3x\right)=24\)
\(125-3x=3\)
\(3x=122\)
\(x=\frac{122}{3}\)
\(5x+\left(3x-11\right)=69\)
\(5x+3x-11=69\)
\(8x=80\)
\(x=10\)
\(5\left(x-1\right)+4x=4\)
\(5x-5+4x=4\)
\(9x=9\)'
\(=1\)
TÌNH BẰNG CÁCH HỢP LÝ
a, 27x36 + 73 x 99 + 27 x 14 - 49 x 73 b, 21 x (271 + 29 ) + 79 x ( 271 + 29)
c, (4^5 x10 x 5^6 + 27^5 x 2^8) : (2^8 x 5^4 x 5^7 x 2^5)
giúp mik với
a, 27x 36 + 73 x 99 + 27 x 14 - 49 x 73
= 27 ( 36 + 14 ) + 73 ( 99 - 49 ) = 27 x 50 + 73 x 50
= 50 ( 27 + 73) = 50 x 100 = 5 000
b, 21 x (271 + 29 ) + 79 x ( 271 + 29)
= (271 + 29 ) ( 21 + 79)
= 300 x 100 = 30 000
c)2x-49=5.3^2
d)2^x=32
e)4^x:16=4
f)(x-1)^3=8
g)7x-x=5^21:5^19+3.2^2-7^0
h)64<x^3<bằng 125
i)25<bằng 5^x<bằng625
c) 2x - 49 = 5 . 32
2x - 49 = 5 . 9
2x - 49 = 45
2x = 45 + 49
2x = 94
x = 94 : 2
x = 47
Tìm x,biết:
A) 8 + ( x - 9)= 125 - 64
B) 5×(x+7) -10 = 8×5
C) 7 × 7 - 7( 13 - 2× x) = 14
D) 320 : (x - 1) = ( 125 - 5 ×5 ) : 4 + 15
E) 240 : ( x -5 ) = 4 × 5 ×5 - 60 : 3
F) 49 × x - 14 × x = 49 × 10 - 70
a. 8 + (x - 9) = 125 - 64
8 + (x - 9) = 61
x - 9 = 53
x = 62
b. 5 x (X + 7) - 10 = 8 x 5
5 x (X + 7) - 10 = 40
5 x (X + 7) = 50
X + 7 = 10
X = 3
(5x+1)2=36/49
(3x-2)5=-243
5x=125
(3x2-51)2n=(-24)2n (n thuoc N*)
(5x+1)2=36/49
(5x+1)2=\(\left(\frac{6}{7}\right)^2\)
5x+1=6/7
5x=-1/7
x=-1/35
5x=125
5x=53
x=3
(3x-2)5=-243
(3x-2)5=(-3)5
3x-2=-3
3x=-1
x=-1/3