Tính nhanh:
a) 1326 + 538 - 326 + 62;
b) 2391 - 147- 253;
Tính nhanh:
a)32.19+32
b)43.17+29.57+13.43+57
c)1326+538-326-38
d)375:25-125:25
a, Ta có : 32.19+32=32.(19+1)
=32.20
=640
1.Tìm x , biết :
a)35.(x-10)=35
b)21.(32-x)=21
c)25.(2x.4).12=0
d)(x-4):6-5=10
e)485-(6.x+60)=5
f)315+(135-x)=450
g)346+(210-x)=556
h)(x-32)-68=0
i)274-(9.x+18)=4
j)442+(418-x)=860
k)107+(210-x)=317
l)x-280:35=5.54
m)(x-120):35=5
n)(x+100)=800
o)x.5+10.9=990
p)x-120:30=40
q)(x+120):20=8
r)(x+5).3=300
s)x.2+21:3=27
2.Tính nhanh
a) 99 - 97 + 95 - 93 + 91 - 89 + ... + 7 - 5 + 3 -1
b)47.8 - 27.9 + 47.12 - 27.11
c) 1326 +538-326-62
d) 2391-147-253
e) 8-96+94-92+90-88+...+7-5+3-1
f) 24.42-35.24-24.7
g)42.13-22.5+42.22
h)125:4-25:4
i)1159:125-159:125
*Lưu ý : các dấu (.) bằng với dấu nhân nhé
a) 35.(x-10)=35
x-10= 35:35
x-10= 1
x= 1+10
x= 10
b) 21.(32-x) =21
32-x = 21:21
32-x = 1
x= 32-1
x= 31
a)\(35.\left(x-10\right)=35\Rightarrow x-10=35:35=1\Rightarrow x=10+1=11\)
b) \(21.\left(32-x\right)=21\Rightarrow32-x=21:21=1\Rightarrow x=32-1=31\)
c) \(25.\left(2x.4\right).12=0\Rightarrow25.\left(2x.4\right)=0:12=0\Rightarrow2x.4=0:25=0\)
\(\Rightarrow2x=0:4=0\Rightarrow x=0:2=0\)
Thực hiện các phép tính sau bằng hai cách:
a) 12 1 2 + 5 3 8
b) 28 1 2 + 2 5 3
a. Cách 1: 12 1 2 + 5 3 8 = 25 2 + 43 8 = 100 8 + 43 8 = 143 8 = 17 7 8
Cách 2: 12 1 2 + 5 3 8 = 12 4 8 + 5 3 8 = 17 7 8
b. Cách 1: 28 1 2 + 2 5 3 = 57 2 + 11 3 = 171 6 + 22 6 = 193 6 = 32 1 6
Cách 2: 28 1 2 + 2 5 3 = 28 3 6 + 2 10 6 = 30 13 6 = 32 1 6
1326+528-326-38
\(1326+528-326-38\)
\(=1584-326-38\)
\(=1528-38\)
\(=1490\)
Chúc bạn học tốt~~~
Trả lời:
1326 + 528 - 326 - 38
= (1326 - 326) + (528 - 38)
= 1000 + 490
= 1490
Hok tốt!
Vuong Dong Yet
Đặt tính rồi tính.
326 + 253 432 + 261 732 + 55 643 + 50
\(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{326}\\{253}\end{array}}\\\hline{\,\,\,\,579}\end{array}\) \(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{432}\\{261}\end{array}}\\\hline{\,\,\,\,693}\end{array}\)
\(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{732}\\{\,\,55}\end{array}}\\\hline{\,\,\,787}\end{array}\) \(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{643}\\{\,\,\,50}\end{array}}\\\hline{\,\,\,\,693}\end{array}\)
1326+326=????
Nhớ kết bn với mình nha.Mình tick cho
Tính nhanh:
a, 64 + -97 + -64
b, -111 + 53 + 11 + -53
c, -409 + 62 + 209 + -72
d, -97 + -15 + -3 + -85
e, -1973 + -51 + 2073 + 51
a, 64 + -97 + -64
=[64 + (-64)] + (-97)
=0 + (-97)
=-97
đặt tính rồi tính :
a) 62 868 : 156 b) 12 345 : 253
14 892 : 73 15 683 : 124
62868:156=403
14892:73=204
12345:253=48(dư 201)
15683:124=126(dư 59)
Tính Nhanh
a, 117 x ( 36 + 62 ) - 17 x ( 62 + 36 )
b, ( 532 x 7 - 266 x 14 ) x ( 532 x 7 + 266 )
c, 506 x 5 + 1012 + 253 x 6
a) = 117 x 100 - 17 x 100
= ( 117 - 17 ) x 100
= 100 x 100
= 10000
b) ( 532 x 7 - 266 x 14 ) x ( 532 x 7 + 266 )
= 532 x 7 - 266 x ( 2 x 7 ) x 3990
= 532 x 7 - 266 x 2 x 7 x 3990
= (532 x 7 - 532 x 7) x 3990
= 0 x 3990
= 0
c) 506 x 5 + 1012 + 253 x 6
= 506 x 5 + (506 x 2) + 253 x ( 2 x 3 )
= 506 x 5 + 506 x 2 + 253 x 2 x 3
= 506 x 5 + 506 x 2 + 506 x 3
= 506 x ( 5 + 2 + 3 )
= 506 x 10
= 5060
a ) 117 x ( 36 + 62 ) - 17 x ( 62 + 36 )
= ( 117 - 17 ) x 98
= 100 x 98
= 9800