36+578+962+514+852
Tính bằng cách hợp lý:
A = 512 x 4 + 512 x 58
B = 312 x 36 - 312 x 26
C = 745 x 11 - 745
D = 837 x 15 - 837 x 5
E = 578 x 78 - 578 x 14 + 578 x 36
F = 645 x 78 + 645 x 22
A = 512 x 4 + 512 x 58
A = 512 x (4 + 58)
A = 512 x 62
A = 31 744
B = 312 x 36 - 312 x 26
B = 312 x (36 - 26)
B = 312 x 10
B = 3120
C = 745 x 11 - 745
C = 745 x (11 - 1)
C = 745 x 10
C = 7450
D = 837 x 15 - 837 x 5
D = 837 x (15 - 5)
D = 837 x 10
D = 8370
E = 578 x 78 - 578 x 14 + 578 x 36
E = 578 x (78 - 14 + 36)
E = 578 x 100
E = 57 800
F = 645 x 78 + 645 x 22
F = 645 x (78 + 22)
F = 645 x 100
F = 64 500
\(\text{B = 312 x 36 - 312 x 26}\)
\(B=312\times\left(36-26\right)\)
\(B=312\times10\)
\(B=3120\)
Tính bằng cách thuận tiện nhất :
a. 388 + 36 + 514 + 12
b. 1249 + 356 - 249
bỏ ngoặc rồi tính
5) (27+514)-(486-73)
6)(36+79)+(145-79-36)
7) 10-[12-(-9-1)]
a) (27+514)-(486-73)
=27+514-486+73
=541-486+73
=55+73
=128
b) (36+79)+(145-79-36)
=36+79+145-79-36
=115+145-79-36
=260-79-36
=181-36
=145
c) 10-[12-(-9-1)]
=10-12+(-9)+(-1)
=(-2)+(-9)+(-1)
=(-11)+(-1)
=-12
tick nha bạn
5)27+514-486+73
6)36+79+145-79-36
7)10-12-9-1
(27+514)-(486-73)
=27+514-486+73
=(27+73)-(486+514)
=100-1000
=(-10)
2. Bỏ ngoặc rồi tính :
a. 111 + ( - 11 + 27 )
b. ( 27 + 514 ) - ( 486 - 73 )
c. ( 36 + 79 ) + ( 145 - 79 - 36 )
a. 111 + (-11 + 27)
= 111 - 11 + 27
= 100 + 27
= 127
b. (27 + 514) - (486 - 73)
= 27 + 514 - 486 + 73
= (27 + 73) + (514 - 486)
= 100 + 28
= 128
c. (36 + 79) + (145 - 79 - 36)
= 36 + 79 + 145 - 79 - 36
= (36 - 36) + (79 - 79) + 145
= 0 + 0 + 145
= 145
a/ = 111+(-11)+27
tự tính
b/ 27+514 - 486+73
tự tính
c/ 36 + 79 + 145 - 79 - 36
tick mk nha bn
a. 111 + ( -11 + 27 )
= 111 - 11 + 27
= 100 + 27
= 127
Câu b, c làm tương tự
Bỏ ngoặc rồi tính:
a) -7264 + (1543 + 7264) b) (144 - 97) - 144 c) (-145) - (18 - 145)
d) 111 + (-11 + 27) e) (27 + 514) - (486 - 73) f) (36 + 79)+ (145 - 79 - 36)
a: \(-7264+\left(1543+7264\right)\)
\(=-7264+1543+7264\)
\(=\left(-7264+7264\right)+1543\)
=0+1543
=1543
b: \(\left(144-97\right)-144\)
\(=144-97-144\)
\(=\left(144-144\right)-97\)
=0-97
=-97
c: \(\left(-145\right)-\left(18-145\right)\)
\(=-145-18+145\)
\(=\left(-145+145\right)-18\)
=0-18
=-18
d: \(111+\left(-11+27\right)\)
\(=\left(111-11\right)+27\)
=100+27
=127
e: \(\left(27+514\right)-\left(486-73\right)\)
\(=27+514-486+73\)
\(=\left(27+73\right)+\left(514-486\right)\)
\(=100+28=128\)
f: \(\left(36+79\right)+\left(145-79-36\right)\)
\(=36+79+145-79-36\)
\(=\left(36-36\right)+\left(79-79\right)+145\)
=0+0+145
=145
a) (36 - 79) + (150 + 79 – 36) b) (27 - 514) – (486 – 73)
c) (35 – 42 + 14) – (35 + 58 – 86) d) (125 – 153 + 87) – (125 – 13 + 47)
e) ( 1267 - 196) - (267 + 304) g) 1152 –(374 + 1152) + (- 65 + 374)
a)
=36-79+150+79-36
=36-36-79+79+150
=150
b)
=27-514-486+73
=27+73-514-486
=-900
c)
=35-42+14-35-58+86
=35-35-42-58+14+86
=0
d)
=125-153+87-125+13-47
=125-125-153-47+87+13
=-100
e)
=1267-196-267-304
=1267-267-196-304
=500
g)
=1152-374-1152-65+374
=1152-1152-374+374-65
=-65
a)
=36-79+150+79-36
=36-36-79+79+150
=150
b)
=27-514-486+73
=27+73-514-486
=-900
c)
=35-42+14-35-58+86
=35-35-42-58+14+86
=0
d)
=125-153+87-125+13-47
=125-125-153-47+87+13
=-100
e)
=1267-196-267-304
=1267-267-196-304
=500
g)
=1152-374-1152-65+374
=1152-1152-374+374-65
=-65
tính hợp lý nếu có thể
a) 36 - 44 + 76 - 89- 56
b) ( 342 - 567) - [ 642 - ( 767 - 458 ) ]
c) 1892 - [ 892 + ( - 852 + 300 ) + 852
d) ( 472 - 281 - 513 ) - ( 372 - 181 + 487)
e) ( 912 - 1268 ) - [ 812 - ( 1368 - 100 )]
Lời giải:
a. $=(36+76)-89-(44+56)$
$=112-89-100=12-89=-(89-12)=-77$
b. $=342-567-642+767-458$
$=(342-642)+(767-567)-458=-300+200-458=-100-458=-(100+458)=-558$
c. $=1892-892+852-300-852$
$=(1892-892)+(852-852)-300=1000+0-300=700$
d.
$=472-281-513-372+181-487$
$=(472-372)-(281-181)-(513+487)$
$=100-100-1000=-1000$
e.
$=912-1268-812+1368-100$
$=(912-812)+(1368-1268)-100=100+100-100=100$
BÀI 2: BỎ NGOẶC RỒI TÍNH (ghi rõ từng bước của phép tính)
1) -7264 + (1543 + 7264)
2) (144 – 97) – 144
3) (-145) – (18 – 145)
4) 111 - (-11 + 107)
5) (27 + 514) – (486 – 73)
6) (36 + 79) + (145 – 79 – 36)
1) - 7264 + ( 1543 + 7264 )
= ( - 7264 + 7264 ) + 1543
= 0 + 1543
= 1543
2) ( 144 - 97 ) - 144
= ( 144 - 144 ) - 97
= 0 - 97
= - 97
3) ( - 145 ) - ( 18 - 145 )
= ( - 145 + 145 ) - 18
= 0 - 18
= - 18
4) 111 - ( - 11 + 107 )
= ( 111 + 11 ) + 107
= 122 + 107
= 229
5) ( 27 + 514 ) - ( 486 - 73 )
= ( 27 + 73 ) + ( 514 - 486 )
= 100 + 28
= 128
6) ( 36 + 79 ) + ( 145 - 79 - 36 )
= ( 36 - 36 ) + ( 79 - 79 ) + 145
= 0 + 0 + 145
= 145
1) - 7264 + ( 1543 + 7264 )
= ( - 7264 + 7264 ) + 1543
= 0 + 1543
= 1543
2) ( 144 - 97 ) - 144
= ( 144 - 144 ) - 97
= 0 - 97
= - 97
3) ( - 145 ) - ( 18 - 145 )
= ( - 145 + 145 ) - 18
= 0 - 18
= - 18
4) 111 - ( - 11 + 107 )
= ( 111 + 11 ) + 107
= 122 + 107
= 229
5) ( 27 + 514 ) - ( 486 - 73 )
= ( 27 + 73 ) + ( 514 - 486 )
= 100 + 28
= 128
6) ( 36 + 79 ) + ( 145 - 79 - 36 )
= ( 36 - 36 ) + ( 79 - 79 ) + 145
= 0 + 0 + 145
= 145
Tính bằng cách thuận tiện :
a) 456 x 65 + 456 x 34 + 456
b) 962 x 115 - 962 x 16 + 962
a,456*65+456*34+456
=456*65+456*34+456*1
=456*(65+34+1)
=456*100
=45600
a) = 456 x ( 65 + 34 + 1 )
= 456 x 100
= 45600
a ) 456 x 65 + 456 x 34 + 456
= 456 x 65 + 456 x 34 + 456 + 1
= 456 x ( 65 + 34 + 1 )
= 456 x 100
= 45600
b ) hong bít
Mik làm theo suy nghĩ nên k đúng hay sai cx đc nhen :))