35+(-42)+75+(-58)
Bài 4: Tính nhanh
1/ 5 . 25 . 2 . 16 . 4 2/ 25 . 5 . 4 . 27 . 2 3/ 23 . 17 - 23 . 17 4/ 58 .75 + 58 . 50 – 58 . 25 | 5/ 125 . 98 – 125 . 46 – 52 . 25 6/ 136 . 23 + 136 . 17 – 40 . 36 7/ 5 . 23 + 35 . 41 + 64 . 65 8/ 29 . 87 – 29 . 23 + 64 . 71 |
a, 35 x 34 + 35 x 38 + 65 x 75 + 45 x 65
b, 39 x 8 + 60 x 2 + 21 x 8
c, 58 x 75 + 58 x 50 - 58 + 25
d, 125 x 98 - 125 x 46 - 52 x 25
a.35 x 34 + 35 x 38 + 65 x 75 + 45 x 65
= 35 x (34 + 38) + 65 x 75 + 65 x 45
= 35 x 72 + 65 x (75+45)
= 35 x 72 + 65 x 120
= 35 x 72 + 65 x (72 + 48)
= 35 x 72 + 65 x 72 + 65 x 48
= (35+65) x 72 + 65 x 48
= 100 x 72 + 65 x 48
= 7200 + 3120
= 10320
b.39 x 8 + 60 x 2 + 21 x 8
=39 x 8 + 15 x 4 x 2 +21 x 8
= 39 x 8 + 15 x 8 + 21 x 8
=(39 + 15 + 21) x 8
= 75 x 8
= 600
c.58 x 75 + 58 x 50 - 58 + 25
= 58 x 75 + 58 x 50 - 58 x 1 + 25
= 58 x(75+50-1)+25
= 58 x 124 + 25
= 7192 + 25
= 7217
d.125 x 98 - 125 x 46 - 52 x 25
= 25 x 5 x 98 - 25 x 5 x 46 - 25 x 52
= 25 x 490 - 25 x 230 - 25 x 52
= 25 x (490 - 230 - 52)
= 25 x 208
= 5200
tinh nhanh :
\((135-35).(-37)+37.[(-42)-58]\)
a) [58+(-42)] -(58-42)
b) (65-35)-(35+27)
c) 3.5^2-176:2^3
d) 2^2.3-5.2^3
g)2020-[39-(5-1)^2]-2019
k) 2018:[38-(7-1)^2]+2018^0
a, [ 58+(-42)]-(58-42)
= 58 - 42 - 58 + 42
= ( 58 - 58 ) + ( 42 - 42)
= 0+0=0
b, ( 65 - 35 ) - ( 35 + 27 )
= 65 - 35 - 35 - 27
= 65 - 70 -27
= 65 - 97
= -32
c, 3 . 52 - 176 : 23
=3 .25 - 176 : 8
= 75 - 22
= 53
d, 22 . 3 - 5 . 23
= 4 . 3 - 5 . 8
= 12 - 40
= -28
g, 2020 - [ 39 - ( 5 - 1 )2 ] - 2019
= 2020 - [ 39 - 42 ] - 2019
= ( 2020 -2019 ) - [ 39 - 16 ]
= 1 - 23
= -22
k, 2018 : [ 38 - ( 7 - 1 )2 ] + 20180
= 2018 : [ 38 - 62 ] + 1
= 2018 : [ 38 - 36 ] + 1
= 2018 : 2 + 1
= 1009 + 1 =1010
a)\(\left[58+\left(-42\right)\right]-\left(58-42\right)\)
=\(58-42-58+42\)
=\(0\)
b)\(\left(65-35\right)-\left(35+27\right)\)
=\(65-35-35+27\)
=\(-32\)
c)\(3.5^2-176:2^3\)
=\(75-22\)
=\(53\)
d)\(2^2.3-5.2^3\)
=\(2^2\left(3-10\right)\)
=\(-28\)
g)\(2020-\left[39-\left(5-1\right)^2\right]-2019\)
=\(1-\left(39-16\right)\)
=\(-22\)
k)\(2018:\left[38-\left(7-1\right)^2\right]+2018^0\)
=\(2018:2+2018^0\)
=\(1010\)
TÍNH NHANH:
a) 6625 + 3525 - 25 b) 58 x 42 + 32 x 8 + 5 x 16
c) (4243 + 4357 + 43) - 360 : 4 d) 35 x 34 + 35 x 86 + 65 x 75 + 65 x 45
a) 6625 + 3525 - 25 d) 35 x 34 + 35 x 86 + 65 x 75 + 65 x 45
= 6625 + ( 3525 -25) = 35 x (34 + 86 ) + 65 x (75 + 45 )
= 6625 + 3500 = 35 x 120 + 65 x 120
= 10 125 = 120 x ( 35 + 65 )
= 120 x 100
= 12 000
a) 6625 + 3525 - 25
=10125
b) 58 x 42 + 32 x 8 + 5 x 16
= 2436 + 256 + 80
= 2772
c) (4243 + 4357 + 43) - 360 : 4
= 8643 - 360: 4
= 8642 - 90
= 8552
d) 35 x 34 + 35 x 86 + 65 x 75 + 65 x 45
= (34 +86) x 35 + (75 + 45) x 65
= 120 x 35 + 120 x 65
= 120 x (35+65)
= 120 x 100
= 12000
( x + 176 ) + 203 = 861 + 42
75 - ( x + 20 ) = 92 - 58
1) (x+176)+203=861+42
(x+176) + 203 = 903
x+176 = 903- 203
x + 176 = 700
x = 700-176
x = 524
2)75 - (x+20) = 92-58
75 - (x+20) =34
x+20 = 75-34
x+20 = 41
x = 41-20
x = 21
ủng hộ nhé
( x + 176 ) + 203 = 903
( x + 176 ) = 903 - 203
( x + 176 ) = 700
x = 700 - 176
x = 524
mình đầu tiên k mình nha
75 - ( x + 20 ) = 34
( x + 20 ) = 75 - 34
( x + 20 ) = 41
x = 41 - 20
x = 21
k mình nha
75/35-48/42+5/6
\(\dfrac{75}{35}\) - \(\dfrac{48}{42}\) + \(\dfrac{5}{6}\)
= \(\dfrac{15}{7}\) - \(\dfrac{8}{7}\) + \(\dfrac{5}{6}\)
= \(\dfrac{7}{7}\) + \(\dfrac{5}{6}\)
= 1 + \(\dfrac{5}{6}\)
= \(\dfrac{11}{6}\)
\(\dfrac{75}{35}-\dfrac{48}{42}+\dfrac{5}{6}=\dfrac{15\times5}{7\times5}-\dfrac{8\times6}{7\times6}+\dfrac{5}{6}\)
\(=\dfrac{15}{7}-\dfrac{8}{7}+\dfrac{5}{6}=\dfrac{15-8}{7}+\dfrac{5}{6}\)
\(=\dfrac{7}{7}+\dfrac{5}{6}=1+\dfrac{5}{6}=\dfrac{6}{6}+\dfrac{5}{6}\)
\(=\dfrac{11}{6}\)
Tính diện tích hình thang biết a=58 cm,b=42,h=35?
(17+35-42+58-23-45):79=?
20 bn xong đầu tiên mik k cho nha