Tìm x :
x+53 = 78
14 . x = 28
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
98216=7814+X+2580
X =98216-7814-2580
X =87822
CHO MK NHA
K CHO MK NHA
\(\frac{31}{53}.\frac{17}{28}+\frac{31}{28}.\frac{11}{53}\)
\(=\frac{31}{53}.\frac{17}{28}+\frac{11}{28}.\frac{31}{53}\)
\(=\frac{31}{53}.\left(\frac{17}{28}+\frac{11}{28}\right)\)
\(=\frac{31}{53}.1\)
\(=\frac{31}{53}\)
\(\frac{31}{53}\times\frac{17}{28}+\frac{31}{28}\times\frac{11}{53}\)
\(=\frac{31}{53}\times\frac{17}{28}+\frac{31}{53}\times\frac{11}{28}\)
\(=\frac{31}{53}\times\left(\frac{17}{28}+\frac{11}{28}\right)\)
\(=\frac{31}{53}\times1\)
\(=\frac{31}{53}\)
a ) 13 x X + 15 = 106
13 x X = 106 - 15
13 x X = 91
X = 91 : 13
X = 7
b ) 19 x X + 53 x X +28 x X = 700
X x ( 19 + 53 + 28 ) = 700
X = 700 : 100
X = 7
~~~ Hok tốt ~~~
( x + 1 ) + ( x + 4 ) + ( x + 7 ) + ( x + 10) + ..........+ ( x + 28 ) = 155
10x + ( 1 + 4 + 7 + ... + 28 ) = 155
10x + 145 = 155
10x = 155 - 145
10x = 10
x = 10 : 10
Vậy x = 1
\(a,\left[x+1\right]+\left[x+4\right]+\left[x+7\right]+\left[x+10\right]+...+\left[x+28\right]=155\)
\(\Leftrightarrow x+1+x+4+x+7+x+10+...+x+28=155\)
\(\Leftrightarrow(x+x+x+...+x)+(1+4+7+...+28)=155\)
\(\Leftrightarrow10x+145=155\)
\(\Leftrightarrow10x=155-145\)
\(\Leftrightarrow10x=10\)
\(\Leftrightarrow x=1\)
\(b)(x\times0,25+1999)\times2000=(53+1999)\times2000\)
\(\Leftrightarrow(x\times0,25+1999)\times2000=4104000\)
\(\Leftrightarrow(x\times0,25+1999)=4104000:2000\)
\(\Leftrightarrow(x\times0,25+1999)=2052\)
\(\Leftrightarrow x\times0,25=2052-1999\)
\(\Leftrightarrow x\times0,25=53\)
\(\Leftrightarrow x=53:0,25=212\)
Câu c tự làm
a) x + 25 = 53
x = 53 - 25
x = 28
b) x - 56 = 28
x = 28 + 56
x = 84
c) 56 - x = 17
x = 56 - 17
x = 39
d) 22 - x = 16
x = 22 - 16
x = 6
x + 25 = 53
x= 53 - 25
x = 28
x - 56 = 28
x = 28 + 56
x = 84
56 - x = 17
x = 56 - 17
x = 39
22 - x = 16
x = 22 - 16
x = 6
\(2b,\)\(54\times47-47\times53-20-27.\)
\(=47\times54-47\times53-47\)
\(=47\times\left(54-53-1\right)\)
\(=47\times0=0\)
\(2c,\)\(10000-47\times72-47\times28\)
\(=100\times100-47\times\left(72+28\right)\)
\(=100\times100-47\times100\)
\(=100\times\left(100-47\right)\)
\(=100\times53=5300\)
2b
54 x 47 - 47 x 53 - 20 - 27 = 47 x ( 54 - 53 ) - 20 - 27 = 47 - 20 - 27 = 47 - ( 20 + 27 ) = 47 - 47 = 0
2c
10000 - 47 x 72 - 47 x 28 = 10000 - 47 x ( 72 - 28 ) = 10000 - 47 x 44 = 10000 - 2068 = 7932
A.35 x 34 + 35 x 38 + 65 x 75 + 65 x 45
Câu này không tính hợp lí được
B. 12x 53 + 53 x 172 - 53 x 84
= 53 x (12 + 172 - 84)
= 53 x 100
= 5300
C. 36 x 28 + 36 x 82 + 64 x 69 + 64 x 41
= 36 x (28+82) + 64 x (69+41)
= 36 x 110 + 64 x 110
= (36+64) x 110
= 100 x 110
= 11 000
D. A = 1+2+3+...+100
= (1+ 100) x 50
= 101 x 50
= 5050
E. B =17+19+...+101+103
= (103 +17) x [(103 - 17):2 + 1]
= 120 x 44
=5280
G. D= 3x (12+13+14+15) + 3x(8+7+6+5)
= 3 x (5+6+7+8+12+13+14+15)
= 3 x (20 x 4)
= 3 x 80
=240
o0oNguyễno0o
x+53=78
x =78-53
x =25
14.x=28
x=28:14
x=2
x+53 = 78
x= 78-53
x= 25
14 . x = 28
x= 28:14
x=2