1/ Tính nhanh
a/ 364 + 225 + 436 b/ 125 x 14 x 25 x8 x4
c/ 36 x 49 x 64 x 49
Tính nhanh
a (-4) x (-3) x 25 x (-8)
b 7x(-25).(-3)2.(-4)
c [93-(20-7)] : 16
d 53-(-51)+(-53)+49
e 168 - (49)+(-68)+4
f 53 -(-7)+(-53)-49
g 25.(-124)+124.25
h (-11).36+64.(-11)
i 125.(-24) +24.125
k 125.(-23)+23.225
l (-11).36+64.(-11)
Giúp mk với!
bài 1 : Tìm x
a) 5 + ( x + 27 ) = 64
b) 64 - ( x - 2 ) = 25
c) 7 - ( x + 5 ) + 14 = 343
d) 5 . x - 25 = 10
e) 4 . ( x - 5 ) - 8 = 48
f) 49 - ( 15 + x ) = 12
g) 49 - 7. ( 13 - x ) = 14
h) 155 - 10. ( x + 1 ) = 55
5 + ( x + 27 ) = 64
( x + 27 ) = 64 - 5 ( x + 27 ) = 59 x = 59 - 27 x = 32a) \(\Rightarrow x+27=59\Rightarrow x=32\)
b) \(\Rightarrow x-2=39\Rightarrow x=41\)
c) \(\Rightarrow x+5=-322\Rightarrow x=-327\)
d) \(\Rightarrow5x=35\Rightarrow x=7\)
e) \(\Rightarrow4\left(x-5\right)=56\Rightarrow x-5=14\Rightarrow x=19\)
f) \(\Rightarrow15+x=37\Rightarrow x=22\)
g) \(\Rightarrow7\left(13-x\right)=35\Rightarrow13-x=5\Rightarrow x=8\)
h) \(\Rightarrow10\left(x+1\right)=100\Rightarrow x+1=10\Rightarrow x=9\)
tính bằng hai cách
786 x ( 32 + 68 )
2904 x 15 + 2904 x 35
436 x 72 - 436 x 42
194 x ( 87 - 7 )
3332 : ( 4 x 49 )
72 : 9 : 8
( 15 x 24 ) : 6
25 x ( 36 : 9 )
C1:
a. 786 x ( 32 +68)
= 786 x 100
= 78600
b. 2904 x 15 + 2904 x 35
= 43560 + 101640
= 145200
c.436 x 72 - 436 x 42
= 31392 - 18312
= 13080
d.194 x (87-7)
= 194 x 80
=15520
e.3332 : (4x49)
= 3332 : 196
= 17
f. 72 : 9 : 8
= (72 : 9) :8
= 1
g. (15 x 24) : 6
= 360 :6
= 60
m. 25 x(36 :9)
= 25 x 4
= 100
Cách 2:
a.786 x 32 + 786 x 68
= 25152 + 53448
= 78600
b. 2904 x ( 15 + 35)
= 2904 x 50
= 145200
c.436 x (72 -42)
= 436 x 30
= 13080
d.194 x 87 - 194 x7
= 16878 - 1358
= 15520
e. 3332 : (4 x 49)
= 3332 : 4 : 49
= 833 : 49 = 17
f. 72 : 9 :8
= 72 : (9 x8)
= 72 : 72
=1
g. (15 x 24) :6
= 15 x (24 :6)
= 15 x 4
= 60
m. 25 x (36 :9)
= ( 25 x36 ):9
= 900 : 9
=100
1,Tính nhanh
a, 568 + 568 x 135 - 568 x 36
b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
c, 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
a, 568 + 568 x 135 - 568 x 36
= 568 x ( 1 + 135 - 36)
= 568 x 100
56 800
b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
= 49 x ( 17 + 37) + 54 x ( 26 + 25 )
= 49 x 54 + 54 x 51
= 54 x ( 49 + 51)
= 54 x 100
= 5 400
c, 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
= ( 2 x 35) x ( 7 x 5) + ( 10 x 7) x 25 + 20 x 70
= 70 x 35 + 70 x 25 + 20 x 70
= 70 x ( 35 + 25 + 20)
= 70 x 80
= 5 600
a) 568 + 568 x 135 - 568 x 36
= 568 x ( 1+1+135-1-36 )
=568 x 100
=5680
b) 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
= 49 x ( 17 + 37 ) + 54 x ( 26 + 25 )
= 49 x 54 + 54 x 51
= 54 x ( 49 + 51 )
= 54 x 100
= 5400
c) 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
= 70 x 35 + 10 x 25 x 7+ 20 x 70
= 70 x 35 + 250 x 7 + 20 x 70
= 70 x 35 + 70 x 25 + 20 x 70
= 70 x (35+25+20)
= 70 x 80
= 5600
Tính nhanh: a) ( 68 x 72 x 49) x ( 27 x 12 – 9 x 36 )
b) ( 25 x 50 – 125 x 10 ) x ( 1 + 2 + 3 + ……….. + 99 + 100
a: \(=68\cdot72\cdot49\cdot\left[324-324\right]=0\)
b: \(=\left(1250-1250\right)\cdot\left(1+...+100\right)=0\)
\(a,\left(68\times72\times49\right)\times\left(27\times12-9\times36\right)=\left(68\times72\times49\right)\times0=0\\ b,\left(25\times50-125\times10\right)\times\left(1+2+...+100\right)=0\times\left(1+2+...+100\right)=0\)
a, ( 68 × 72 × 49 ) × ( 27 × 12 − 9 × 36 ) = ( 68 × 72 × 49 ) × 0 =
b, ( 25 × 50 − 125 × 10 ) × ( 1 + 2 + ... + 100 ) = 0 × ( 1 + 2 + ... + 100 ) = 0
Câu 10. Cho (1 − 1/4) x (1 − 1/9) x (1 − 1/26 ) x (1 − 1/25 ) x (1 − 1/36 ) x (1 − 1/49 ) x (1 − 1/64 ) = , biết là phân số tối giản. Tính = + . A. = 28 B. = 25 C. = 30 D. = 36 mik can gap
Đề bài bạn viết khó hiểu quá. Bạn nên viết lại rõ ràng, mạch lạc, có ngắt nghỉ và xuống dòng hợp lý.
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
bài 1: tính hợp lí
a) 5 x 72 x 10 x 2 b) 40 x 125 c) 4 x 2021 x 25 d) 16 x 6 x 25
bài 2: tính nhanh
a) 24 x 57 + 43 x 24 b) 12 x 19 + 80 x 12 +12
c) (36 x 15 x 169) : (5 x 18 x13) d) (44 x 52 x 60) : ( 11 x 13 x 15)
bài 3: tìm X
a) X - 280 : 35 = 5 x 54 b) ( X - 280) : 35 = 54 : 4
c) ( X - 128 + 20 ) : 192 = 0 d) 4 x ( X + 200) = 460 + 85 x 4
bài 4: thực hiện phép tính
a) 7/12 - 5/12 b) 8/11 + 19/11 c) 3/8 + 5/12 d) 3/4 + 7/12
bài 5: tìm x
a) X - 6/7 = 5/2 b) 12/7 : X + 2/3 = 7/5
`@` `\text {Ans}`
`\downarrow`
`1,`
`a)`
`5 \times 72 \times 10 \times 2`
`= 5 \times 2 \times 10 \times 72`
`= 10 \times 10 \times 72`
`= 100 \times 72`
`= 7200`
`b)`
`40 \times 125`
`= 4 \times 10 \times 25 \times 5`
`= (5 \times 10) \times (4 \times 25)`
`= 50 \times 100`
`= 5000`
`c)`
`4 \times 2021 \times 25`
`= (4 \times 25) \times 2021`
`= 100 \times 2021`
`= 202100`
`d)`
`16 \times 6 \times 25`
`= 4 \times 4 \times 6 \times 25`
`= (4 \times 25) \times 4 \times 6`
`= 100 \times 24`
`= 2400`
`2,`
`a)`
`24 \times 57 + 43 \times 24`
`= 24 \times (57+43)`
`= 24 \times 100`
`= 2400`
`b)`
`12 \times 19 + 80 \times 12 +12`
`= 12 \times (19 + 80 + 1)`
`= 12 \times 100`
`= 1200`
`c)`
`(36 \times 15 \times 169) \div (5 \times 18 \times 13)`
`= 36 \times 15 \times 169 \div 5 \div 18 \div 13`
`= 6 \times 6 \times 3 \times 5 \times 13 \times 13 \div 5 \div 3 \times 6 \div 13`
`= (6 \div 6) \times (3 \div 3) \times (5 \div 5) \times (13 \div 13) \times 6 \times 13`
`= 6 \times 13`
`= 78`
`d)`
`(44 \times 52 \times 60) \div ( 11 \times 13 \times 15)`
`= 44 \times 52 \times 60 \div 11 \div 13 \div 15`
`= 4 \times 11 \times 13 \times 4 \times 15 \times 4 \div 11 \div 13 \div 15`
`= (11 \div 11) \times (13 \div 13) \times (15 \div 15) \times 4 \times 4 \times`
`= 4 \times 4 \times 4`
`= 64`
`3,`
`a)`
`x - 280 \div 35 = 5 \times 54`
`x - 8 = 270`
`x = 270 + 8`
`x = 278`
`b)`
`(x - 280) \div 35 = 54 \div 4`
`(x - 280) \div 35 = 13,5`
`x - 280 = 13,5 \times 35`
`x - 280 = 472,5`
`x = 472,5 + 280`
`x = 752,5`
`c)`
`(x - 128 + 20) \div 192 = 0`
`x - 128 + 20 = 0 \times 192`
`x - 128 + 20 = 0`
`x - 108 = 0`
`x = 0 + 108`
`x = 108`
`d)`
`4 \times (x + 200) = 460 + 85 \times 4`
`4 \times (x+200) = 460 + 340`
`4 \times (x+200) = 800`
`x + 200 = 800 \div 4`
`x + 200 = 200`
`x = 200 - 200`
`x = 0`
`4,`
`a)`
`7/12 - 5/12`
`= (7 - 5)/12`
`= 2/12`
`= 1/6`
`b)`
`8/11 + 19/11`
`= (8+19)/11`
`= 27/11`
`c)`
`3/8 + 5/12`
`= 9/24 + 10/24`
`= 19/24`
`d)`
`3/4 + 7/12`
`= 9/12 + 7/12`
`= 16/12`
`= 4/3`
`5,`
`a)`
`x - 6/7 = 5/2`
`x = 5/2 + 6/7`
`x = 47/14`
`b)`
`12/7 \div x + 2/3 = 7/5`
`12/7 \div x = 7/5 - 2/3`
`12/7 \div x = 11/15`
`x = 12/7 \div 11/15`
`x = 180/77`
`@` `\text {Kaizuu lv uuu}`
tính nhanh
a)(-4)x(+3)x(-125)x(+25)x(-8)
b)(-67)x(1-301)-301x67
(-4).(+3).(-125).(-8)=-12000
b) (-67).(1-301)-301.67= -67