Tìm x, biết:
a. x + 37 = 82
b. x - 34 = 46
Bài 1 tính nhanh
A) 37 x 46 + 37 x 51 + 111
B) 35x 215 -35 x 210 - 175
c) 172 x 47 + 86 x 8 - 34 x4
d) 48 x 56 + 28 x104
a) \(37\times46+37\times51+111\)
\(=37\times46+37\times51+37\times3\)
\(=37\times\left(46+51+3\right)\)
\(=37\times100\)
\(=3700\)
b) \(35\times215-35\times210-175\)
\(=35\times215-35\times210-35\times5\)
\(=35\times\left(215-210-5\right)\)
\(=35\times0\)
\(=0\)
c) \(172\times47+86\times8-34\times4\)
\(=4\times\left(43\times47+86\times2-34\right)\)
\(=4\times\left(2021+172-34\right)\)
\(=4\times2159\)
\(=8636\)
d) \(48\times56+28\times104\)
\(=48\times56+56\times52\)
\(=56\times\left(48+52\right)\)
\(=56\times100\)
\(=5600\)
Tính giá trị biểu thức:
a. 4237 x 18 – 34 578
8064 : 64 x 37
b. 46 857 + 3444 : 28
601 759 – 1988 : 14
a. … = 76 266 – 34 578 = 41 688
… = 126 x 37 = 4662
b. ... = 46 857 + 123 = 46 980
…= 601 759 – 142 = 601 617
tính nhanh
37 x 46 + 37 x 51 + 111
172 x 47 + 86 x8 - 34 x4
35 x 215 - 35 x 210 -175
48 x 56 + 28 x104
\(37\times46+37\times51+111\)
\(=37\times46+37\times51+37\times3\)
\(=37\times\left(46+51+3\right)\)
\(=37\times100\)
\(=3700\)
------------
\(172\times47+86\times8-34\times4\)
\(=172\times47+172\times4-34\times4\)
\(=172\times\left(47+4\right)-34\times4\)
\(=172\times51-34\times4\)
\(=172\times3\times17-17\times2\times4\)
\(=17\times\left(172\times3-2\times4\right)\)
\(=17\times\left(516-8\right)\)
\(=17\times508\)
\(=8636\)
------------
\(35\times215-35\times200-175\)
\(=35\times215-35\times200-35\times5\)
\(=35\times\left(215-200-5\right)\)
\(=35\times10\)
\(=350\)
------------
\(48\times56+28\times104\)
\(=48\times2\times28+28\times104\)
\(=28\times\left(48\times2+104\right)\)
\(=28\times200\)
\(=5600\)
câu 3: Tìm X
a)52-X=25
b)X-34+8=46
a)\(x=52-25=27\)
b)\(x=\left(46-8\right)+34=38+34=72\)
Tìm x thuộc Z, biết:
a) − 2 5 + 1 6 + − 1 5 ≤ x < − 3 4 + 9 7 + − 1 4 + 5 7
b) 5 17 + − 4 9 + 12 17 < x ≤ − 3 7 + 7 15 + 4 − 7 + 8 15 + 9 3
a) − 2 5 + 1 6 + − 1 5 ≤ x < − 3 4 + 9 7 + − 1 4 + 5 7 ⇔ − 13 30 ≤ x ≤ 1 ⇔ x ∈ 0 ; 1
b) 5 17 + − 4 9 + 12 17 < x ≤ − 3 7 + 7 15 + 4 − 7 + 8 15 + 9 3 ⇔ 5 9 < x ≤ 3 ⇔ x ∈ 1 ; 2 ; 3
Tìm số nguyên x biết:
a) 7 + (-x) = (-5) - (-14)
b) 484 + x = (-632) + (-584)
c) 311 - x + 82= 46 + (x - 21 )
d) | x + 9 | = 12
a) 7 + (-x) = (-5) - (-14)
7 + (-x) = 9
-x = 9 - 7
-x = 2
x = -2
Vậy x = -2
b) 484 + x = (-632) + (-584)
484 + x = -48
x = -48 - 484
x = -532
Vậy x = -532
d) | x + 9 | = 12
x + 9 = 12
x = 12 - 9
x = 3
Vậy x =3
a) 7+(-x)=9 b) 484+x= (-632)+(-584)
x=9-7 484+X= -1216
x=2 X=(-1216)+484
X=-732
D) => X+9=12 HOẶC X+9= -12
TH1: TH2;
X+9=12 X+9= -12
X=12-9 X=-12-9
X=3 X=-21
a, 7 + (-x) = 9
-x = 9 - 7
-x = 2
=> x = -2
b, 484 + x = -1216
x = (-1216) - 484
x = -1700
c, 311 - x + 82 = 46 + x - 21
393 - x = 25 + x
393 - 25 = 2.x
368 = 2.x
=> x = 368 : 2 = 184
d, |x + 9| = 12
TH1 : x + 9 = 12 TH2 : x + 9 = -12
x = 12 - 9 x = (-12) - 9
x = 3 x = -21
Tìm x, biết:
a ) x = 1 5 + 2 11 ; b ) x = 1 13 + − 13 26 ; c ) x = 1 12 + 3 4 + − 2 9 ;
d ) x 5 = 5 6 + − 19 30 ; e ) x 7 = 3 7 + − 5 4 ; f ) 11 8 + 13 6 = 85 x ;
a ) x = 21 55 ; b ) x = − 11 26 ; c ) x = 11 18 ; d ) x = 1
d ) x = − 1 ; e ) x = 11 7 ; f ) x = 20
Tìm x :
a/ x3 - 2 . x2 = 0
b/ 311 - x + 82 = 46 + ( x - 21 ) - 3x
a/ x2 .(x -2)=0
suy ra hoặc x2=0
hoặc x-2=0
hoặc cả hai =0
từ đó tính ra x